Preheat oven to 350 degrees F. Line a baking sheet with parchment paper and set aside.
In a medium bowl, whisk together flour, baking powder, baking soda and salt. Set aside.
In a bowl of an electric mixer fitted with the paddle attachment, beat butter on medium speed until creamy.
Add the egg and vanilla extract, and beat until smooth. Gradually add the dry ingredients, beating until just combined. Stir in sprinkles by hand.
Drop dough by rounded tablespoons onto prepared baking sheet. Bake for 15 minutes, or until cookies are golden brown around the edges. Let cool on baking sheet for 5 minutes before transferring to a wire rack to cool completely. Sprinkle with additional sprinkles, if desired.