This cake is heavily inspired by the Great British Bake-Off (known in the US as The Great British Baking Show). The first episode I ever watched was all about cakes and one of the challenges was to design and make a roll cake. I like cake and really wanted to try this challenge for myself. I bought a jelly roll pan just to make this cake and I'm not disappointed.
This cake idea started out as a mocha roll cake and the caramel elements were added at the last minute. I saw a bit of caramel sauce in a jar in my fridge while I was digging for cake ingredients and decided to use it. I also bought stroopwafels (Dutch caramel filled wafer cookies) to serve all by themselves at the party I made this cake for, but decided they would also make the cake look extra fancy.
Notes:
- Since it is a chocolate cake, I sprinkled the towel that holds the rolled cake with cocoa powder instead of powdered sugar (this is primarily for looks).
- I used 1 tsp of espresso granules in the buttercream when I made it and the coffee flavor was very subtle, and not quite strong enough for my liking. I wrote 1 1/2 tsp in the recipe below but if you really like coffee flavor, 2 tsp might be better.
- Adding 1 tbsp of butter at a time to the buttercream = 24 additions = ain’t nobody got time for that. I added 3-4 tbsp at a time and it was fine.
- I initially used 3/4 of the buttercream inside the cake and 1/4 for decoration and it was a bit much. I might consider cutting the filling with plain whipped cream or using a slightly different filling next time.
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RECIPE:
Caramel Mocha Swiss Roll Cake
adapted from
Hershey's (cake),
The Pioneer Woman (filling),
Minimalist Baker (caramel sauce)
Makes 1 cake, serves about 12-16
Chocolate cake:
1/4 cup cocoa powder plus 1/3 cup, divided
4 eggs, at room temperature, separated
1/2 cup granulated sugar plus 1/3 cup, divided
1 tsp vanilla extract
1/2 cup all-purpose flour
1/2 tsp baking powder
1/4 tsp baking soda
1/8 tsp salt
1/3 cup water
Espresso Swiss meringue buttercream:
4 egg whites, at room temperature (reserve yolks for another use)
1 1/2 cups granulated sugar
1 1/2 cups (3 sticks) unsalted butter, room temperature and cut into tablespoons
1 1/2 tsp instant espresso granules mixed with 1 tsp very hot water, cooled to room temperature
1 tsp vanilla extract
1 pinch fine sea salt
Vanilla bourbon caramel sauce:
1 cup sugar
1/4 cup water
½ cup heavy cream
1 tsp pure vanilla extract
1 tbsp bourbon whiskey
Pinch of salt (optional)
Decoration:
Chocolate covered espresso beans and/or mini stroopwafel cookies
Prepare cake: Preheat oven to 375°F. Line a jelly roll pan (15.5 x 10.5 x 1 in) with foil, and generously grease the foil with butter. Set aside. Sprinkle 1/4 cup sifted cocoa powder onto a clean cotton or linen kitchen towel (preferably a dark colored one with no pile/loops) that is at least as large as the jelly roll pan. Place egg whites in a large bowl and beat with a hand mixer until soft peaks form. Add 1/2 cup granulated sugar in several additions, until stiff peaks form. In the bowl of a stand mixer fitted with the paddle attachment, beat the egg yolks with the vanilla extract for about 3 minutes. Add 1/3 cup of granulated sugar in several additions, mixing briefly after each one, and beat for 2 more minutes. In another medium bowl, stir flour, 1/3 cup cocoa powder, baking powder, baking soda, and salt until well blended. With the mixer on low speed, alternate adding flour mixture and water to the egg yolk mixture in several additions, just until the batter is smooth. Fold this batter into the egg whites gently until well blended. Transfer batter to jelly roll pan, distributing evenly, and place in oven. Bake for 12-15 minutes, or until the top of the cake springs back into place when touched lightly in the center. Remove from oven and immediately loosen the cake from the sides of the pan and invert cake onto the cocoa dusted towel. Carefully remove the foil from the cake, then roll cake and towel together from the short side. Transfer rolled cake to a wire rack to cool completely. While cake cools, prepare buttercream and caramel sauce.
Prepare buttercream: Find a medium saucepan that will allow your stand mixer bowl to sit atop it with at least 1 inch of room from the bottom. Fill saucepan with about 1/2 inch of water on high heat until it simmers, then turn heat to low. Put egg whites and sugar in the bowl of a stand mixer, then place the mixer bowl on top of the simmering pan of water, being careful that it does not touch the water's surface. Heat the egg whites and sugar to approximately 160°F, whisking constantly. If you do not have a thermometer, it is ready when and all the sugar is dissolved (it is not grainy when you rub it between your fingers). The mixture will be hot to the touch. Immediately transfer the mixer bowl to the stand mixer and using the whisk attachment, whip on high speed until the mixture is thick and glossy and forms stiff peaks. Once it has reached this stage, continue to whip until the bowl has cooled to room temperature. This process takes roughly 10 minutes. Remove whisk attachment and switch to the paddle attachment. Set mixer to low speed. Drop in 3 tablespoons of the butter and beat until smooth. Repeat this process until all the butter is incorporated. If it appears clumpy or curdled during this process, increase speed to medium-high and beat until it is smooth again. Mix in the espresso, vanilla, and salt on medium speed, beating until smooth.
Prepare caramel sauce: Place sugar and water in a medium saucepan over medium heat, swirling occasionally (not stirring) until the mixture turns a deep amber color. Once it starts to brown, it will darken quickly! Be careful not to let it burn. Remove pan from the heat, turn off the burner, and whisk in the cream, whisking while pouring. The mixture may expand a bit and release a lot of steam when this happens, so be careful. Once the cream is fully incorporated, place pan back on the burner and whisk in the vanilla and bourbon. Mix for about 1 minute, then remove from heat and let cool slightly. Pour into a glass pint jar or other heat-safe container and let cool to room temperature.
Assemble and decorate cake: Carefully unroll the cooled cake and spread half of the espresso buttercream evenly onto the inner surface, leaving a small border on all sides. Warm 1/4 cup of the caramel sauce in the microwave for about 20 seconds, then drizzle back and forth across the top of the buttercream. Reroll cake as tightly as you can manage without it cracking. Place on a serving plate with the seam side down. Trim the ends of the cake so they have a nice flat edge. Drizzle about 1/2 cup warmed caramel sauce in ribbons over the cake across the short side. Fit a piping bag with a medium sized star tip and fill bag with remaining espresso buttercream. Pipe rows of shells or stars along the top center of the cake (mine is shown with one big spiral drawn with a star tip). Decorate with chocolate covered espresso beans and/or mini stroopwafel cookies. Cover loosely with saran wrap and let stand in the refrigerator for several hours to firm up. Remove cake from refrigerator about 30 minutes before serving. Store leftovers loosely covered in the refrigerator for up to 3 days.
