Preheat oven to 375°F. Mix flour, baking powder and baking soda and set aside. In another bowl, mix the butter and sugar until creamy. Beat in the egg. Slowly blend in the dry ingredients. Add milk to make the dough moist. Dust a rolling pin with flour, and roll dough out onto floured wax paper. Roll to about 1/4 inch thick for best results. Add flour as needed to keep the dough from sticking to the rolling pin and waxed paper. Cut out cookies using a cookie cutter (I used a Mickey Mouse cutter).Remove carefully from wax paper and place on a cookie sheet. Cook for 7 minutes. Cool on wire racks. When cookies are cooled you can add icing to them. I just used my standard, quick recipe for icing sugar cookies: Icing sugar and milk. Add more milk for thinner, pourable icing; less for a more spreadable icing. You can add your colours here as well. I used black, yellow and red for the traditional Mickey colours. Let the cookies dry overnight. This allows you to get a rock hard finish on them and they will not stick together when stacked.