Chocolate Roll Cake

The Art.

    It's Christmas baking time, everybody! I've posted quite a few Christmas cookies over the years, including Iced Snowflake Sugar Cookies, Gingerbread Cookies, and a Meringue Christmas Tree. This year, I wanted to step away from the cookies and make a pretty Christmas cake. The idea of making an iced yule log was appealing, but by now everyone has eaten so many sweets they didn't even want to think about icing. So, I settled on this simple Chocolate Roll Cake. A naked dark chocolate sponge filled with barely sweetened whipped cream is the perfect treat for everyone who's had a few too many of Santa's cookies...but still has room for a little more.

The Science.

    The trickiest part of making a roll cake is getting a beautiful swirl shape without any splits or cracks. There are several factors that contribute to success here. First, this cake is a flourless sponge with lots of whipped egg whites that make the cake very elastic and easy to handle. Second, baking the cake on a silicone mat not only prevents the bottom from getting overbaked and dry, but also helps immensely with the rolling process because you can use the mat for support as you roll. And finally, rolling the cake up while it's warm and cooling it in this shape makes a beautiful round roll that won't look squashed in the end.

The Recipe.

Flourless Chocolate Sponge:
6 egg whites, at room temperature
1/4 teaspoon cream of tartar
3/4 cup sugar, divided
6 egg yolks
1/3 cup dark cocoa powder

Preheat oven to 350°F and line a 10in by 15in jelly roll pan with a silicone mat. Whip the egg whites and cream of tartar on medium-high speed until soft peaks form. Gradually add half the sugar while beating, until stiff peaks form. Set aside. In another bowl, combine the remaining sugar, egg yolks, and cocoa powder. Beat on medium-high speed for at least two minutes, making sure to scrape the bowl periodically. Getting this mixture well mixed and fluffy is very important for the texture of the cake. Add 1/4 of the egg whites to the chocolate mixture and stir to lighten the batter. Gently fold in the rest of the egg whites just until combined, making sure not to deflate the batter while doing so. Pour batter onto prepared pan with mat, spreading the top very evenly with a spatula. Bake for 15 minutes, until the center springs back when lightly touched with your fingertip. Cool in the pan for 10 minutes, then run a sharpe knife along the edges to release them from the pan. While the cake is still warm, dust the top with a small amount of cocoa and cover the top with parchment paper (the cocoa prevents sticking). Begin rolling up the warm cake from the short side, rolling up the parchment paper and the silicone mat right along with the cake. Once the cake is rolled, place it on the countertop with the outside edge on the bottom. Support the long sides of the cake with a rolling pin, baking pan, storage jar, or any other long object you have in your kitchen, in order to prevent the roll from sagging while it cools. Meanwhile, make the whipped cream.

Stabilized Whipped Cream:
1 teaspoon gelatin
3 tablespoons boiling water
1 cup heavy whipping cream, chilled
1/4 cup powdered sugar

    Place a metal mixing bowl and metal whisk attachment in the freezer for 15 minutes. Meanwhile, combine gelatin and boiling water in a small bowl and stir until dissolved. Gradually stir whipping cream into the gelatin, going slowly so the gelatin doesn't seize. Place whipping cream and gelatin in the refrigerator for 10 minutes. Whip the cream/gelatin in the chilled bowl with the chilled whisk on medium speed until soft peaks form. Continue beating while gradually adding the powdered sugar, until stiff peaks form. Refrigerate cream until the cake is completely cool.

Assembly:

    Gently unroll the cake and remove the parchment paper from the top, leaving the cake on the silicone mat. Lightly brush away any excess cocoa powder. Spread the whipped cream evenly over the top of the cake, leaving one inch bare on all the edges. Begin rolling up the cake from the short end, the same direction you rolled it before. As you start rolling, gently pull the silicone mat up and away from the cake with one hand as you form a tight cake roll with the other. Using the mat in this way supports the cake and helps you roll it more tightly. You want to roll the cake so that there are no air holes and the center has a nice swirl, but not so tight that you tear the cake. Going slowly and keeping the mat taught will make this easier.
    Once the cake is rolled, place it with the outside edge down on a cake board or serving dish. Cover
with parchment paper and support the long sides once again to keep a round shape. Refrigerate for at least four hours. Before serving, remove the parchment paper and trim off the short ends of the cake (approximately 1/2 inch) with a sharp serrated knife to reveal a beautiful swirl filled with cream. You may arrange the cake board with any decorations you wish; I chose rosemary sprigs, sugared cranberries, and star anise for a rustic Christmas theme. You can also skip the decorations and use a sifter to dust the cake with either powdered sugar or cocoa for a simpler look. Leftover cake can be stored in the refrigerator in an airtight container for up to three days.

Pink Champagne Cake

The Art.

    This past year has treated me pretty well, so I decided to have a birthday celebration that my sister described as "extra." Printed invitations, wine, charcuterie, and this beautiful cake with pink champagne icing. You can tell I went all out because I splurged on a bottle of Pannier Brut Rose Champagne, which might have had something to do with the fact that the label matched my pink and gold theme. Gold edible confetti, glitter cake picks, and a table scattered with pink and gold confetti completed the look. Champagne is inherently celebratory, so you could also make this cake for a wedding shower, graduation, or anytime you would like to pop open a bottle.

The Science.

    Even with all of the glittery decorations, the champagne icing is what really makes this cake stand out. I had great success blending liquor into meringue icing for my Elderflower Cupcakes a while back, but this time I wanted an icing that was more sturdy for decorating. With this in mind, I decided to make a Swiss meringue buttercream. By adding the champagne to the cooked meringue first, the bite of the alcohol evaporated off, leaving the light fruity taste of the pink champagne. Cooking off the moisture in this step also helps the butter incorporate into the meringue at the end.

The Recipe.

    For the cake, follow the white cake instructions from my Orange Creme Cake, except pour the batter into three 6 x 3 inch round pans coated with baking spray and lined with parchment paper. If you would like a pink ombre effect, you can divide the batter into bowls and add pink food color before pouring into the pans. After baking, invert cakes onto a wire rack to cool completely. If you would like to make cupcakes as well, make a double batch of batter and pour the rest into lined cupcake tins and bake cupcakes for approximately 17 minutes.

Pink Champagne Swiss Meringue Buttercream:
4 large egg whites, at room temperature
1 cup sugar
1/2 cup rose champagne or sparkling wine
1 pound (4 sticks) butter, at room temperature
1/4 teaspoon sea salt
pink food color

    Bring 1 inch of water to a simmer in a small saucepan. Place the egg whites, sugar, and champagne in a medium metal bowl, then place the bowl over the simmering saucepan to make a double boiler. Make sure the bottom of the bowl is not touching the water, we only want the steam to cook the egg whites gently as they whip. Using a hand mixer, beat the mixture on high speed for 5 minutes, until stiff peaks form. Remove from heat, and continue to whip until the meringue is cool, about 2 minutes. Gradually add the butter while beating on high, 2 tablespoons at a time. Add the sea salt and food color and beat until completely incorporated and the icing is smooth. 

Assembling the cake:

    Level off any crown on your cake layers with a serrated knife. This will ensure that you have a beautiful, even cake in the end. Place the bottom cake layer on a rotating cake stand (or a flat plate or stand you can turn with one hand). Spread with icing, then place the next cake layer, and repeat. Once you have all three cake layers, cover the entire cake with a thin crumb coat of icing. Using an offset spatula or long knife, spread another layer of icing onto the cake. In order to get perfectly smooth icing, I used this icing smoother while slowly rotating the stand. 

   To decorate, I pressed Wilton Gold Edible Heart Accents onto the cake, in a gradient going up the sides to mimic champagne bubbles. I then placed the cake on a gold cake board and decorated with gold glitter cake picks. For the cupcakes, I piped a swirl of icing with a 1M tip and sprinkled with the gold hearts. To complete the display, I scattered gold and pink confetti on the table and displayed the beautiful champagne bottle alongside. The cake can be stored in an air-tight container in the refrigerator for up to one week. However, water condensation might make the edible confetti disintegrate into the icing so it's best if the confetti is added shortly before serving.

Swiss Meringues

The Art.

    One of the baking projects I wanted to accomplish this winter was to make a beautiful drip cake piled high with macarons, meringues, and candies. The end result was my Candyland Drip Cake and I had a lot of fun putting it together. It was also very intensive, since I wanted to make the meringues and macarons myself. I made a previous post featuring Italian meringues, but this time around I wanted the glossy, delicate shape of Swiss meringues piped with a French tip. The crisp texture and airiness of these cookies accompany tea or coffee perfectly. I suggest making them on a weekend while you are doing your chores, since they require a couple hours in the oven.

The Science.

    The difference between Italian and Swiss meringues is that Italian meringue is beaten at room temperature, whereas Swiss meringue is heated. When egg whites are beaten at high speeds, the albumin protein in the egg whites begins to bind together and aggregate [1]. This traps little air bubbles incorporated by the whisk, making a fluffy meringue. Cream of tartar further aids in the protein aggregation by stabilizing the tangled proteins. In the case of Swiss meringue, the heat provides energy to the aggregation reactions and results in a stiffer meringue with smaller bubbles. 

    I also wanted to share with you an unexpected finding I had regarding food color. The very first batch of meringues I made was dyed with my staple Wilton gel icing colors. I was surprised to find that the blue meringues were cracked and full of large bubbles, while the white ones were fine. Of course, my chemist of a husband took one look at them and said it was because the gel food coloring was cooking up faster than the meringue, causing some parts to shrink rapidly and pull the cookies apart. So, my suggestion to all of you is to use standard liquid food coloring if you want your cookies to come out right!

The Recipe.

Meringue cookies: (Makes 50) 

3 large egg whites

1 tablespoon pure vanilla extract

1/4 teaspoon cream of tartar

3/4 cup superfine granulated sugar

liquid food color (optional)

    Preheat oven to 200°F. Bring a medium saucepan with 1 inch of water to a simmer; this will be the bottom part of your double boiler. Combine all ingredients (except the food color) in a large heat-proof bowl. Place the bowl over the steaming saucepan and whip the egg whites on high speed with a hand mixer for 5 minutes. Be sure to have an oven mitt on the hand that is stabilizing the bowl so the steam doesn't burn you. The meringue should make stiff peaks on your beaters when you pull them out of the bowl. Remove the bowl from the heat and continue to beat on high speed until the meringue cools to room temperature, about 2 minutes. This is when you may whisk in the food color if you wish.

     Cover two baking sheets with parchment paper, sticking the paper down at the corners with a dab of meringue. Spoon meringue into an piping bag fitted with a 6B tip, and pipe 1-inch stars onto the baking sheets, 1/2 inch apart.  Bake 2 hours, switching the top and bottom racks halfway through. After baking, leave cookies in the oven to cool 1 hour with the door held ajar a couple inches with a spoon handle. Meringues can be stored at room temperature in an air-tight container.

1. O Chef, "Beating Egg Whites into Submission." http://www.ochef.com/223.htm

Candyland Drip Cake

The Art.

    This is my first foray into drip cakes, and I'm kicking myself that it took me so long! I was intimidated by all the beautiful cakes I had seen with bright icing dripping down in perfect little streams, and I imagined that my attempt would either be a runny mess or a clumpy defeat. However, I am happy to report I got it on the first try! You can, too, with the right chocolate and a few easy tricks. My favorite part about drip cakes is that they are usually piled high with other treats, such as these airy Swiss Meringues and Raspberry Macarons. The recipes for these are coming soon as well, so stay tuned!

The Science.

    I did quite a bit of research on the best way to make chocolate ganache before I began, but I was frustrated that everyone had wildly different recipes. In the end I concluded that it comes down to the type of chocolate that you use, and whether you want a more matte ganache like this one, or a shiny one. I used Ghirardelli white chocolate melting wafers for this cake because they taste absolutely amazing and I wanted something that was easy to melt and work with. However, you can use a wide variety of chocolates or melting wafers for your cake. The trick is determining the ratio of chocolate to cream that is best for your particular chocolate. For my Ghirardelli wafers, it was about 3 volumes of chocolate wafers to 1 volume of cream. For harder bar chocolate, like dark chocolate, it will be closer to equal amounts. Unfortunately I can't give a hard and fast rule for this, you will have to take some time to melt your favorite chocolate and play with the ratios until you get it right. This is why you always buy extra chocolate and cream-- in addition to the fact that chocolate does tend to mysteriously disappear when I'm in the room!

The Recipe.

Cake:

   For this cake, I made a 4-layer spice cake using 6x3inch round tins. The recipe for spice cake can be found here. I then leveled the layers flat with a knife and assembled and iced the cake with a batch of buttercream icing. Place the cake in the freezer for at least an hour before you add your drip ganache, so it doesn't stream down the cake too quickly.

Drip Ganache:

6oz. Ghirardelli White Chocolate Melting Wafers

2oz. Heavy Cream

    Combine chocolate and cream in a microwave safe bowl, and microwave in 30 second intervals, stirring between, until just melted. It is important to wait for the ganache to cool slightly before you spoon it onto the cake. It has reached the right temperature when it drips slowly off of your spoon, like thick honey.

    To begin decorating your drip cake, use a teaspoon to pick up some ganache, and slowly pour it onto the cake, about 1/4 inch away from the edge. Stop pouring slightly before the drip reaches the length you want it to be, as it will continue to drip down. Continue to do this at regular intervals around the cake, varying the length of the drips. Finally, use the remaining ganache to flood the top of

 the cake, but be careful not to spill it over the edges.

    To decorate this cake, I used a variety of shapes, textures, and sizes to make a visually interesting pile of sweets. It's very in vogue to place macarons on top of cakes right now, and if you don't have time to make your own you can buy them in most every color to match your desired color scheme. I liked adding the Swiss meringues piped with a French tip because the star shapes provide contrast against the round cookies and candies. It's also always a good idea to have smaller candies that you can use to fill in gaps once you get the big cookies on there. The best part is when you serve the cake and each piece gets an extra treat!

Matcha Sakura Petits Fours

The Art.

    One of my favorite things about my visit to Japan last fall was all the pastries. When I discovered that the entire ground floor of Daimaru department store was devoted to desserts, I almost refused to come back the US. This spring, I was reminiscing about our trip and thinking about how wonderful it would be to go back during sakura season. I decided to make little Japanese-inspired springtime petits fours to tide me over until I can visit again. Since I ran into matcha flavored EVERYTHING while we were there, I started out with matcha flavored cake and icing. I also discovered this amazing sakura blossom paste that is absolutely to die for, so I used that as the filling in the petits fours. Topping the cakes off with pink blossoms brings together the sakura blossom theme!

The Science.

    Matcha is a bright green tea that is made by shading tea plants before they are harvested. This causes the leaves to produce more green chlorophyll, so they can make more energy from the little sunlight they get. This method produces tea with a strong, distinctive flavor. One of the things I noticed while I was testing recipes was the difference in color and flavor between different matcha powders. I researched this a little bit, and came across an amazing thing I didn't know about: there are electronic intelligent instruments called the E-nose and E-tongue that detect odors and flavors! These instruments have "diverse sensors generating different signature phenomena to fully exploit the characteristics of test samples," and are paired with sophisticated computer algorithms to predict what a person would taste and smell from the tea [1]. In plain English, the E-nose and E-tongue can "smell" and "taste" the way humans do. Many food scientists have quantified the compounds that give matcha its distinct flavor by mass spectrometry [2,3], and the E-nose and E-tongue use this information to generate a flavor profile from the tea and give it a grade classification. This technology, in addition to being really cool, is used to eliminate the variation between human tasters and the influence of their taste preferences on the tea's classification. I just can't get over the fact that there are tea-tasting robots! Do they have tea parties?

The Recipe.

Matcha cake:
3 egg whites, divided
3/4 cup sugar, divided
1 cup cake flour
1 1/2 teaspoons baking powder
5 grams matcha powder 
1/3 cup salted butter 
1 teaspoon vanilla
2/3 cup buttermilk
Sakura paste (filling)

    Preheat oven to 350°F. Coat a 9x13 inch baking pan with baking spray, and line with parchment paper. Beat 2 egg whites and 1/4 cup sugar together on high speed until stiff peaks form. Set aside. Beat together butter, sugar, vanilla, and remaining egg white. In another bowl, combine flour, baking powder, and matcha. Alternately add one third of the flour mixture and buttermilk to the butter mixture, beating between each addition just until combined. Fold in beaten egg whites with a spatula. Spoon batter into pan and smooth the top with a spatula. Bake on center rack for 15 minutes, or until tester comes out clean. Cool 10 minutes in pan, then invert onto wire racks to cool completely.

Matcha poured fondant:
4oz Ghirardelli white bar chocolate 
5 grams matcha powder
6 cups powdered sugar
1/2 cup water
2 tablespoons light corn syrup

   Heat chocolate in a large microwave-safe bowl in 30-second bursts, stirring inbetween, until melted.  Add matcha. Stir in powdered sugar, 1 cup at a time, adding small amounts of water at intervals. Stir in corn syrup. Icing will be very thick. If desired, tint the icing a brighter green with gel icing colors.

Assembly:
    To make pretty petits fours, you must be very accurate while cutting your cake. First, level the top of the cake with either a cake leveler or a long serrated blade. Next, get out your ruler and cut your cake straight down the middle to create two 9x7.5 inch pieces.  Spread a thin layer of sakura paste on one side and top it with the second cake layer. Get your ruler out again, and cut your cake into one-inch strips. Carefully score the top of your cake strips into one-inch squares with your serrated knife, then very gently cut your petits fours with a slow sawing motion.
    To ice the petits fours, balance one cake on a fork over the bowl of poured fondant. Spoon fondant over the cake and then allow to dry on a wire rack. You may want to coat the petits fours once more to give them a nice smooth finish. Before the second layer dries, top with pink gum paste blossoms. Either pipe some icing into the flower center or add edible pearls to complete your cherry blossoms.
    Store petits fours in the fridge for up to one week, or freeze if storing longer.

References:

1. Zhi, R et al. "A Framework for the Multi-Level Fusion of Electronic Nose and Electronic Tongue for Tea Quality Assessment." Sensors (Basel). 2017 May 3;17(5). pii: E1007. doi: 10.3390/s17051007.

2. Wang, L.F. et al. "The Compounds Contributing to the Greenness of Green Tea." Journal of Food Science, 69: S301–S305. doi:10.1111/j.1365-2621.2004.tb09894.x

3. Lee, Lan-Sook et al. "Metabolomic Analysis of the Effect of Shade Treatment on the Nutritional and Sensory Qualities of Green Tea." J. Agric. Food Chem., 2013, 61 (2), pp 332–338

DOI: 10.1021/jf304161y

Chocolate Strawberry Mint Cake

The Art.

    One of the first plants I grew as a kid were little strawberries planted outside my bedroom window. My favorite thing about strawberries is how pretty the vines are, so I made a beautiful cake covered in strawberry vines and flowers. This is the first time I've used my gum paste flower set and I would highly recommend it. The small and medium flower cutters are the perfect size for strawberry blooms, and painting them ever so slightly pink with food color gives them dimension. Hiding under the buttercream and mint leaves are two layers of dark chocolate cake separated by more fresh strawberries. I have to admit, I usually I wouldn't combine so many flavors, but in this case they blend together perfectly for a fresh, spring cake!

The Science.

    One of the things that surprised me about this cake is that everyone assumed the icing was mint flavored. I had only intended to use the mint leaves as an edible decoration, and it didn't occur to me that they would have so much impact on the flavor. I think the real reason for this is that I accidentally extracted the essential oils of the mint into the icing. Most of you probably remember from high school chemistry that fats and oils are "hydrophobic," or water-hating. And also the rule that "like dissolves like," meaning that if you want to dissolve something hydrophobic, you use another hydrophobic solvent. These principles are what lead to the happy accident that is the faux mint buttercream. The fats in the butter and shortening in the icing dissolved the flavorful oils from the mint leaves, enhancing the flavor of the icing with a fresh, mint flavor. This has inspired me to try to incorporate fresh mint into my icing in the future, hopefully with the same wonderful results!

The Recipe.

    The recipes for chocolate cake and buttercream icing can be found here and here. This cake was made using two 6x3-inch pans. Spread buttercream on the bottom cake layer and arrange with fresh strawberries, then top with the second layer. 

    I dyed most of the remaining icing light blue using Wilton Icing Colors Teal, and a small amount with Kelly Green. After smoothing the cake with blue icing, use a small round decorating tip to pipe the vines. Adorn the cake with mint leaves, gum paste flowers, and halved strawberries. If your strawberries have nice leaves, you may keep them on. Mine did not, so I improvised and used some of the smaller mint leaves. Refrigerate cake until serving to prevent the mint leaves from wilting. The cake will look its best if served within one day.

Berry Valentine Cake

The Art.
    Happy Valentine's Day! For those of you who have been around for a while, you know how much I love Valentine's Day. If you're new around here, just check out my Valentine Petit Fours, Burnin' Love Sriracha Truffles, Roses are Red Cake, or Gluten Free Corset Cookies and you'll get the idea. This year, I have a beautiful berry cake to share with you. I deviated from the usual chocolate chocolate chocolate motif and made this cake using my angelfood cake recipe and filled it with some silky Bavarian cream. Decorating this cake with fresh berries and miniature roses makes it sweet, romantic, and easy to finish off.

The Science.
    For this cake, I wanted to create a whipped icing with true blueberry flavor.  I didn't want to use blueberry jam because I wanted a fresh taste without getting it too sweet. I knew this would be tricky, since simply pureeing fresh berries and adding them to the cream would add too much water and make it hard to whip up. So instead I made a blueberry reduction by heating the blueberries in a saucepan and boiling down the strained juices. While I was doing this I learned that it takes a lot more berries than you would think to create a punch of flavor, so don't skimp on the blueberries!

The Recipe.
     Prepare the angelfood cake as for the Roses are Red Cake, and a batch of Bavarian Cream. You will also need fresh berries and miniature roses for decorating.

Blueberry Whipped Icing:
1 pint blueberries
1 cup 40% heavy whipping cream
1 teaspoon cornstarch
1/4 cup powdered sugar


    Place a metal bowl and your mixer beaters in the freezer to cool. Wash blueberries and place in a small saucepan on low heat. Stir occasionally and cook approximately 20 minutes, until berries have released all their juices. Remove fruit with a strainer and press down on the strainer with a spoon to reserve the remaining juices in the saucepan. Continue to heat the juices for about 10 minutes until they begin to thicken and reduce down to 1/4 cup. Allow reduction to cool.
    In your cooled bowl, beat the whipping cream on medium speed until it begins to thicken. Add blueberry reduction, cornstarch and powdered sugar. Beat on medium speed until stiff peaks form.

Assembly:
    Place one cake layer on cake stand. Cover with approximately 1/2 cup Bavarian cream. Top with second cake layer. Smooth the whipped icing over the cake with an offset spatula. You will have lots of leftover Bavarian cream and whipped icing, which you can serve alongside the cake. Decorate with fresh berries and miniature roses. Store covered in the fridge until serving. Cake can be made ahead one day.