For the egg liqueur cake, beat the eggs with the powdered sugar until frothy. Add the vanilla sugar and lemon.
Then slowly drizzle in the oil and the eggnog. Finally, fold in the flour and baking powder.
Pour half of the mixture into a cake mold. Then stir the cocoa into the remaining mixture and then pour it into the mold as well.
Bake the egg liqueur cake at 160° C for about 50 minutes.