You'll never want brownies any other way.
- Preheat oven to 350 degrees Fahrenheit. Grease a 9x13 baking dish with cooking spray.
- Prepare brownie batter according to package instructions.
- Spread 1/2 of the brownie batter into baking dish. Drop spoonfuls of marshmallow fluff over brownie batter. Cover with 3/4 of the crushed Oreo cookies. Top with remaining brownie batter, chocolate chips and remaining Oreo cookies.
- Bake for 28 to 30 minutes. Remove from oven and allow to cool.
- Serve and enjoy!