Whisk together flour, baking powder, and salt in a bowl. Set aside.

In a mixer fitted with the paddle attachment, cream margarine and sugar until light and fluffy. Add egg and vanilla and beat on high speed until combined. Scrape down the sides of the bowl and repeat as needed.

Add in the dry ingredients and mix on low until combined. Add sprinkles and mix to incorporate. The dough will be thick and slightly sticky. Scoop out two tablespoons of dough and roll into a ball. For extra fun, sprinkle cookies with additional sprinkles. Place on a Gefen Parchment-lined baking sheet and refrigerate for at least two hours.

Arrange the cookie dough balls at least three inches apart and bake for 11 to 12 minutes. Let cool for at least five minutes before transferring to a cooling rack.

Preheat the oven to 350 degrees Fahrenheit.