Separate the whites from the yolks. Place the yolks in a separate bowl, and place the whites in a tall beaker. Add a pinch of salt to the whites and beat until stiff peaks form.
Then add the yolks to the whites and mix the ingredients until smooth.
In a deep bowl, mix sifted flour, sugar, salt and cocoa.
Add the dry ingredients mixture to the eggs. Mix the dough until smooth.
Grease the baking pan with soft butter. Pour the dough into the pan. Bake in the oven for 30-40 minutes at 180 ⁰С.
Let the sponge cake cool down a bit and remove it from the mold. Decorate the surface of the sponge cake with powdered sugar. Enjoy!