Preheat oven to 350°F. Line baking sheets with parchment paper.
In a large bowl, cream butter and sugar until light and fluffy.
Add egg and vanilla extract; mix until combined.
In a separate bowl, whisk together flour, baking powder, and salt.
Gradually add dry ingredients to the wet ingredients, mixing until a dough forms.
Fold in ¼ cup sprinkles.
Scoop dough into balls and place on prepared baking sheets. Slightly flatten each ball and top with more sprinkles.
Bake for 10-12 minutes or until edges are just beginning to brown.
Let cool on the pan for 5 minutes before transferring to a wire rack to cool completely.