Combine the sprinkles into a bowl and set aside
Preheat the oven to 350 degrees and spray a 12x8 baking pan with pam baking spray
Using a standing mixer, beat the melted butter, brown sugar, and sugar until combined and smooth
Beat in the eggs and egg yolk, one at a time until combined and smooth
Beat in the vanilla extract
Using a medium bowl, whisk together the flour, baking powder, cornstarch, and salt
Gradually beat the dry ingredients into the batter until a soft dough formsFold in the golden oreo crumbs, half of the chopped Oreos and half of the sprinkles
Scoop the batter into the baking pan and spread evenly
Sprinkle the rest of the chopped golden Oreos around the top of the batter
Sprinkle the rest of the sprinkles on top
Bake in the oven for 25-35 minutes or until a toothpick comes out clean
To avoid burning, cover with foil the last 10 minutes of baking
Allow cooling before cutting into bars
Enjoy