Whisk together the flour, baking powder and salt in a small bowl.
Beat the sugar and butter with an electric mixer on medium speed in a large bowl until light and fluffy, about 5 minutes; beat in the egg, then the vanilla. Add the flour mixture and sprinkles and mix on medium-low speed until completely incorporated. Divide the dough in half, place each piece between 2 pieces of parchment and then roll to 1/3 inch thick. Once rolled out, place the parchment sandwiches dough on a baking sheet and chill for 20 minutes.
Position oven racks in the top and bottom thirds of the oven and preheat to 350 degrees F. Line 2 baking sheets with parchment paper.
Cut out shapes with the cookie cutters and arrange about 2 inches apart on the prepared baking sheets.
Bake until the cookies are golden brown on the bottom, 10 to 12 minutes. Let the cookies cool on the baking sheets until firm enough to transfer to a wire rack; let cool completely.
Gently gather any scraps into a ball and press into a disc; wrap in plastic wrap and refrigerate the disc until firm enough to roll, about 1 hour. Cut out as many cookies as possible and bake.
