Chocolate sponge cake is a universal baking recipe that can be used as a basis for making various cakes and pastries, adding cream and filling to taste and desire. The biscuit (chocolate or regular) should be light and fluffy. The main conditions for this are to thoroughly beat the eggs, cook the dough without sudden movements, and do not disturb the biscuit in the oven when baking.
Beat until fluffy, stable white mass (10-20 minutes).
Gradually pour the cocoa flour into the beaten egg mass, stirring gently and slowly.
Grease the mold with oil.
Put the dough in a greased form and bake the chocolate sponge cake in the oven preheated to 175-180 degrees until cooked (40-50 minutes) without opening the oven door.