How to make
Beat the butter with the powdered sugar with a mixer until you get a smooth cream. In a bowl in a water bath on the stove, beat the eggs with the granulated sugar until the mixture turns white and thickens.
Mix the cocoa into it well and remove it from the heat. Pour the egg cream spoon by spoon into the butter one, while beating with the mixer and beat the two mixtures together.
Flavour it with vanilla if desired or other essence and use it for cakes.