Chocolate Sponge Cake – Ingredients:
- 1/2 cup cake flour
- 1/2 cup cocoa powder
- 6 tablespoons unsalted butter, plus extra for greasing
- 1 tablespoon vanilla extract
- 1/2 cup sugar
- 5 large eggs
- 5 large egg yolks
Preheat oven to 375 degrees F. Lightly spray 8- or 9-inch round cake pans with a nonstick spray and lines the bottoms with a round of parchment paper. For cupcakes, prepare pans with cupcake liners.
Sift the flour and cocoa powder together twice and set aside.
Melt the butter in a saucepan over low heat. Remove from the heat, add the vanilla extract to the melted butter, and stir to combine. Set aside to cool.
Combine the sugar, eggs, and egg yolks in the bowl of a stand mixer and set the bowl over a pan of barely simmering water. Whisking constantly with a wire whisk, heat until the mixture is warm to the touch or reaches 120 degrees F on a candy thermometer.
Remove the bowl from the heat and attach it to a stand mixer fitted with the whisk attachment. Whip the egg mixture on medium speed until the foam triples in volume and just begins to recede about 5 minutes. Stabilize the foam at low speed for 10 minutes.
Fold the flour into the egg mixture using a rubber spatula. Blend a small amount of the batter into the melted butter, then fold the tempered butter back into the remaining batter.
Fill the prepared cake or cupcake pans about two-thirds full. Bake until the top of each layer is firm to the touch – for 8- or 9-inch cakes about 30 minutes, for cupcakes about 20 minutes.
Let the layers cool in the pans for a few minutes before turning out onto wire racks to finish cooling.
The cakes are ready to fill and frost now, or they can be wrapped and stored at room temperature for 2 days, or frozen for up to 3 weeks.