Preheat your oven to 350°F (175°C). Grease or line a baking dish with parchment paper.

In a large bowl, cream together softened butter, granulated sugar, and brown sugar until light and fluffy. Add eggs one at a time and mix in vanilla extract.

In another bowl, whisk together flour, baking powder, and salt. Gradually add dry ingredients to the wet mixture until just combined.

Gently fold in half of the sprinkles into the batter. Spread evenly into the prepared dish and top with remaining sprinkles.

Bake for 25-30 minutes until golden brown around the edges. Let cool completely before cutting into squares.