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

Cream together the softened butter, granulated sugar, and brown sugar until light and fluffy. Add eggs one at a time and incorporate the vanilla extract.

Whisk together the flour, baking powder, and salt in another bowl. Gradually add these dry ingredients to the wet mixture, stirring until just combined.

Fold in half of the colorful sprinkles gently into your batter, then spread into the prepared dish and top with the remaining sprinkles.

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

Optional: Dust with powdered sugar for an extra touch of sweetness before serving.