1 cup butter, softened
1/2 cup confectioners' sugar
1/4 cup cornstarch
1 1/2 cups all-purpose flour
2T colored sugar or sprinkles
Preheat the oven to 375 degrees F (190 degrees C).
Whip butter with an electric mixer until fluffy, about 5 minutes. Stir in the confectioners' sugar, cornstarch, and flour. Beat on low for one minute, then on high for several more minutes. Add the sprinkles and mix to combine.
Using a small cookie disher or a spoon, drop 1T round onto a cookie sheet. Cut these in quarters and rearrange them to allow space for them to grow. Tip: using a silpat or baking sheet on your cookie sheet allows for more even baking and they are easier to get off when they are cooked.
Bake for 12 to 15 minutes in the preheated oven. Cool on racks.