For Cookies: Mix butter and sugar in a bowl until creamy and smooth. Next, add in eggs and vanilla and beat. Add flour, baking powder and salt into mixture, stirring until well combined. Cover the bowl and place in refrigerator to chill for at least an hour. After the dough has chilled, preheat oven to 400 degrees Fahrenheit. Roll out dough into a ¼ inch thick sheet on a floured surface. Use a cookie cutter to cut out shapes. Place cookies on an ungreased cookie sheet at least an inch apart from each other. Bake 6 to 8 minutes. Cool completely before icing cookies. For Icing (if desired): Mix ingredients together in a bowl using a fork. Apply icing to cookies using a spoon or brush. Add a pinch of sprinkles, if desired.
Tips: To make icing more of a thin glaze, add more milk. To make it thicker, add more powdered sugar. Makes 5 Dozen