Prepare the Sponge Cake Base
- 1
Preheat your oven to 200°C (390°F) top/bottom heat. Grease a 26cm springform pan well and lightly dust it with flour or cocoa.
- 2
Put the eggs and sugar into a heatproof bowl and warm them over a double boiler or over very low heat in a pot, stirring constantly, to 45°C (113°F). Use a thermometer for this.
- 3
Remove the bowl from the double boiler and beat the egg-sugar mixture with a hand mixer or in a stand mixer on the highest setting for about 25 minutes until it is very light, thick, and foamy, and its volume has significantly increased.
25 min - 4
In a separate bowl, mix the sifted flour, baking cocoa, and baking powder well together.
- 5
Carefully fold the dry ingredients into the beaten egg mixture in several portions. Be careful not to knock out too much air.
- 6
Add the vanilla extract and the melted, slightly cooled butter and carefully fold them in until everything is well combined.
- 7
Pour the batter into the prepared springform pan and bake the sponge for about 30 minutes. Do the skewer test: If you insert a wooden skewer into the center of the cake and it comes out clean, the base is ready.
30 min - 8
After baking, let the sponge cake base cool briefly in the pan, then release the springform rim and let the base cool completely on a wire rack before continuing to process it.