Pre heat oven to 350°F

In a medium saucepan melt 10 tbsp butter over medium high heat. Ass 1 1/4 cup white sugar and cocoa powder once the butter is melted. Whisk to combine and remove from heat. Add 1/2 tsp salt, 2 tsp vanilla, and 2 eggs and continuously whisk until combined. Add 1/2 cup flour and continue to mix. Set aside

Cream together 1/2 cup butter, 3/4 cup white sugar, and brown sugar in mixer. Add 1 egg, 1 1/4 tsp vanilla, then add 1 1/4 cup flour, 1/2 tsp salt, baking soda and baking powder and mix on low. Fold in chocolate chips. Set aside

Line bottom of 9x9 baking pan with foil and spray with cooking spray

Layer cookie dough on bottom of pan

Layer Oreos on top of cookie dough

Pour brownie batter on top of Oreos

Bake for 30-35 minutes