Add 1-2 tsp of Baileys liqueur to the dry mixture and stir with a spatula to get the mixture going. If it's still lumpy, add another 1 tsp of liqueur and stir again.
Add the rest of the liqueur with a spray bottle by slowly spritzing it onto the mixture until it reaches the proper consistency of a "15 second" icing. When a knife cuts through the icing, it will take 15 second for the cut to disappear.
Pipe desired design onto the gingerbread men and wait at least 12 hours for the icing to dry before adding edible paint on top.