Preheat an oven to 350°F and spray a 9"x13" baking pan with nonstick cooking spray.

In a stand mixer with the paddle attachment, mix flour, sugar, baking powder, and salt until mixed.

To the flour mixture add the butter until combined and then the eggs, vanilla, and milk. Increase speed to medium-high and beat until light and fluffy, about 1 minute then gently stir in the sprinkles.

Pour the batter in to pan and smooth the top, then bake 25-30 minutes and do not turn out until completely cooled.