How to make
Prepare a baking pan with a diameter of 9.5″ (24 cm), which needs to be greased with butter and sprinkled with flour.
If you use a ring cake tin, line it with baking paper.
In two bowls divide the yolks and whites. Beat the yolks for 5 minutes on medium speed, then add 1/2 of the sugar.
Proceed in the same way with the egg whites - beat them into a white mixture.
Carefully mix the egg ingredients with a spatula to preserve their volume.
Gradually add the melted in a water bath and cooled butter.
Sift the flour into a bowl along with the baking powder and cocoa. Also add the vanilla.
Mix the dry with the liquid ingredients. Mix them well.
Pour the finished mixture into the cake tin and place it in a preheated oven.
Bake the sponge cake layer at 360°F (180°C) for 40 minutes.