Sponge cake dough
Description
Break the eggs and separate the egg whites from the yolks. Beat the egg whites in a bowl with a mixer at high speed until foamy. In a separate bowl, mix the yolks with sugar. Carefully add 1/3 of the beaten whites to the yolks, gently mix, then add the sifted flour and vanilla sugar. Add the remaining beaten whites and knead the batter until smooth and uniform. Preheat the oven to 200–220°C. Grease a baking pan or tray with butter and sprinkle with breadcrumbs or flour (alternatively, line it with parchment paper). Place the prepared batter onto the baking tray or into the pan. The pan should be filled to 3/4 of its height, as the sponge cake will rise during baking. Bake the sponge cake in the preheated oven for 20–35 minutes, until golden brown. To check doneness, use a wooden skewer—when inserted into the center, it should come out dry. Let the sponge cake cool in the pan or on the tray, then transfer it to a wire rack and allow it to cool completely. If the sponge cake does not come out of the pan easily, carefully run a knife along the inner edges and turn it over.