Step 1

Preheat oven to 350°F (177°C). Line cookie sheet with parchment paper or silicone baking mat. Set aside. Pour 1/4 cup sprinkles onto a plate to use for rolling. Set aside.

Step 2

Cream the butter and sugar together on medium speed using a handheld or stand mixer with a paddle attachment. Beat in egg yolk, butter extract, baking powder, and salt. Add flour, and mix until a dough forms. Dough will be thick. Gently mix in sprinkles.

Step 3

Roll dough in teaspoon size balls. Make sure that the balls are tall, rather than wide. The taller the cookie dough ball, the thicker the cookie will be. Roll the dough balls into the reserved sprinkles and bake for 9-10 minutes. Watch them closely at the 9 minute mark to assure they do not brown.

Step 4

Allow cookies to cool for 2 minutes on the cookie sheets before transferring to a cookie rack to cool completely. Cookies remain fresh up to 1 week covered at room temperature.