Halloween Peanut Butter Oreo Brownie Bar

1/2 cup butter, softened
1 cup peanut butter
1/2 cup white sugar
1/2 cup brown sugar, packed
1 egg
3 tablespoons milk
1 teaspoon vanilla extract
1 1/4 cups all-purpose flour
3/4 teaspoon baking powder
1/4 teaspoon salt
1 (9.9 oz) pkg white chocolate candy corn M&Ms or 1 cup Reese’s Pieces
1 pkg Halloween or Double Stuffed Oreos
1 Family Size (9—13) Brownie mix
1/4 cup hot fudge topping

Preheat oven to 350 degrees F. Cream the butter, peanut butter,
and both sugars in a large bowl with an electric mixer on medium speed for 3-5 minutes.
Add the eggs, milk and vanilla and beat until dough is light and fluffy.
In a separate bowl, whisk together the flour, baking powder and salt,
then slowly add to the mixer until the flour is just combined. Stir in M&Ms.
Spray a 9×13 baking dish with cooking spray, line with wax paper, and spray with cooking spray again.
Spread the cookie dough in the bottom of the dish. Top with a layer of Oreos.
Mix together brownie mix, adding an optional 1/4 cup of hot fudge topping to the mix.
Pour the brownie batter over the cookie dough and Oreos.
Bake at 350 degrees F for 45-55 minutes, until a toothpick inserted 2" from the edge comes out with moist pieces clinging to it.