250 grams of wheat flour
125 grams of butter
150 grams of sugar
15 grams of cocoa powder
3 teaspoons of baking powder
50 ml of milk
1 pinch of salt
First of all, we will grease with butter, the mold that we are going to use and then we will sprinkle flour on top.
In a bowl, mix the flour together with the yeast, sifted. In the mixer, we will beat the butter (at room temperature) together with the sugar, until the mixture is whitish and smooth.
Gradually add 3 egg yolks and 1 whole egg to the sugar mixture and continue beating. Reserve the remaining egg whites. Add the sifted flour and milk to this mixture and beat.
In a separate bowl, beat the 3 egg whites together with a pinch of salt, whip until stiff. Add the egg whites to the previous dough, stir well. Divide the dough in two and separate into two containers.
To one of the parts, add the cocoa powder, mix well. Add to the mold, greased at the beginning, a layer of natural dough, another of dough with cocoa, one of natural, one of cocoa… and so on until the dough is finished, with this procedure we will get the famous sponge cake.