The perfect combination of crushed oreo cookies, a chocolate brownie and marshmallows. These Mississippi Mud Brownies easily hit the spot.
Preheat oven to 350 degrees F. Grease a 9×9 inch baking pan.
Pull out 1/8 cup of crushed Oreos and set aside. Spread the rest of the Oreo Cookie crust into the bottom of the pan with the melted butter and press firmly. Bake in the oven for 8-10 minutes on 350 degrees.
In a medium bowl, mix together the oil, sugar, and vanilla. Beat in eggs. Combine flour, cocoa, baking powder, and salt; gradually stir into the egg mixture until well blended. Fold in the marshmallows. Set aside.
Remove from oven and layer on the brownie mix. Sprinkle the rest of the crushed Oreos on the top of the brownie mix in clumps.
Bake for 20 to 25 minutes, or until the brownie begins to pull away from edges of pan. Let cool on a wire rack before cutting into squares.