Cream together butter and sugar until smooth. Beat in eggs and vanilla. In small batches, add in the flour, baking powder and salt. Cover and chill dough for one hour or overnight. I often freeze half the batch to do at a later date. Preheat oven to 400. Roll out dough on floured surface and cut into shapes with cookie cutter. Bake 6-7 minutes and cool completely before decorating.
For the icing:
