Melt the chocolate in a water bath, use any leftover Santa Clauses. Mix the butter, sugar, vanilla sugar and the egg with the hand mixer and add the melted chocolate.
Mix the flour with the baking powder and cocoa powder and add to the other ingredients. Chill the entire mixture in the refrigerator for 1 hour.
Then form balls. Roll these in powdered sugar and bake at 180 ° C on the middle rack for 12-15 minutes. The balls can also be rolled in powdered sugar after baking.