I’ve made this one with a peppermint whipped cream filling, rich chocolate ganache on the outside, and a crushed peppermint candy sprinkled on top, giving it a particularly festive, wintry air. The light, springy cake practically melts in your mouth. If you’re looking for a show-stopper dessert for your holiday table, this is it. I based the sponge cake part of this recipe on a classic chocolate genoise. This style of cake doesn’t contain any leaveners, like baking soda or baking powder. Instead, it relies on eggs to get its lift. To make sure the eggs whisk into a strong, stable foam (which in turn helps make a reliable and delicious cake), you warm them briefly with the sugar over a double-boiler.
Using a Double Boiler
A double boiler just involves warming a few inches of water in a medium-sized saucepan and setting a bowl over top. The bowl should rest on the lip of the saucepan above the water, like an egg in an eggcup. It’s ok if the bowl touches the water, but it shouldn’t touch the bottom of the pan. Whisking the eggs in a double boiler warms them gently without risk that they will overcook or curdle. You’ll also use a double boiler later in the recipe to melt the chocolate for the ganache; in that instance, the double boiler helps melt the chocolate evenly and without scorching.
How to Roll Up a Swiss Roll
There’s really only one other daunting moment in this recipe—rolling up the cake! The trick for this is to roll the cake around a clean kitchen towel while it’s still warm from the oven, then letting it cool in this position before frosting. Rolling and cooling the cake like this gives it the ability to hold the rolled shape without cracking. To add the frosting, you’ll just gently unroll it, remove the towel, then frost it and roll it back up. The process requires a bit of confidence, but if you work swiftly, you’ll be amazed at how simply the roll comes together. Once the cake has been filled, all that’s left to do is drizzle it with chocolate ganache and sprinkle some crushed peppermint over top. You’re ready to slice and serve! Once the ganache is added, the cake is best served the day it is made (the ganache won’t look as pretty the second day). Leftover cake that doesn’t get devoured can be stored, covered, in the fridge for up to 3 days.
Nonstick cooking spray, for greasing the pan
1/3 cup all-purpose flour
1/4 cup unsweetened cocoa powder, plus extra for rolling the cake
1/8 teaspoon kosher salt
6 large eggs
2/3 cup sugar
1 teaspoon vanilla extract
4 tablespoons unsalted butter, melted and cooled (but still liquid)
For the peppermint whipped cream
1 1/4 cups heavy whipping cream
2 tablespoons sugar
1 teaspoon peppermint extract
For the ganache and peppermint topping
1/2 cup heavy cream
4 ounces bittersweet chocolate, chopped, divided
1 teaspoon light corn syrup
1/4 cup crushed peppermint candies or candy canes
Begin whisking the eggs, sugar, and vanilla extract with a sturdy whisk. Continue whisking until the sugar has dissolved and the egg mixture is pale and warm to the touch. Remove from heat. Drizzle the melted, cooled butter into the mixture and gently mix to combine. While the cake is baking, prepare a kitchen towel for rolling. Find a clean kitchen towel that is larger than your baking sheet (or use two, overlapping). Dust it all over with cocoa powder. Fold the edge of the towel over one of the shorter sides of the cake and gently roll the cake up. Set the rolled cake log on a wire rack and cool completely, an hour or longer. Add the heavy cream, 2/3 of the chopped chocolate, and a pinch salt to the bowl. Stir until melted. Remove the bowl from heat, and stir in remaining chocolate and corn syrup.
