In a large mixing bowl using an electric mixer combine the butter and sugar until light and fluffy. Beat in egg and vanilla. Mix in the flour and baking powder.
The dough will start out crumbly, but work it with your hands until you reach a good consistency.
Flour your rolling surface and roll the dough to ¼-½ inch thickness. Cut out donut shapes and place cut outs on a parchment or silpat lined baking sheets.
Bake at 350°F for 8-9 minutes or until the bottoms just start to turn golden. Transfer baked cookies to a cooling rack.
While cookies are cooling, combine 1 cup powdered sugar, corn syrup, milk, and 2 - 4 drops of food coloring in a shallow medium sized bowl. Whisk with a fork until smooth adding more powdered sugar as needed until desired consistency is reached.
Dip each cookie face down into the icing, place back onto the wire rack, and top with sprinkles right away. Allow the icing to set (about 30 - 60 minutes).
Notes
Calories are automatically generated. For best results calculate based on your exact ingredients.*Makes 16 - 24 cookies depending on the size of your cutters and how thinly you roll out the dough. *If you don't have donut cookie cutters, try the combo of a coffee mug and water bottle top to cut out the shapes!