Preheat the oven to 350°F and line a baking sheet with parchment paper.
In a mixing bowl, beat the butter and sugar together until smooth and creamy.
Add the egg and vanilla extract to the butter mixture and stir until combined.
In a separate bowl, whisk together the flour, baking powder, and salt.
Gradually mix the dry ingredients into the wet ingredients until a soft dough forms.
Fold half of the sprinkles into the dough.
Scoop rounded tablespoons of dough onto the baking sheet and press the remaining sprinkles gently onto the tops.
Bake for 10 to 12 minutes until the edges turn lightly golden.
Cool the cookies on the baking sheet for 5 minutes before moving them to a wire rack.