How to make
Beat the butter with the sugar, add the egg yolks one at a time, then add all the other products, except the cocoa. You need to get soft dough. In 1/3 of it, beat the cocoa.
In a greased and lightly floured mold, put half the white dough, the cocoa mixture and then the remaining white dough. Put the golden cake to bake in a moderate oven until it turns golden brown and cracks.
Remove the cake from the form before it has cooled completely and sprinkle it with powdered sugar.