Beat butter with sugar, eggs and vanilla flavor until creamy. Add Irish Cream, or simply add milk if you wish. Sift the flour and cocoa with the coffee powder into the remaining ingredients. Stir in the baking powder and salt. Chop and fold in both types of chocolate.
Chill the dough for 4-6 hours or overnight.
Preheat the oven to 180 ° C top / bottom heat.
Meanwhile, shape about 30 small balls out of the dough and then bake for about 10 minutes.