- 1 (19.8 ounce) package brownie mix
- 1/2 cup vegetable oil
- 1/4 cup water
- 2 eggs
- 1 (10.5 ounce) package miniature marshmallows
- 2 cups semisweet chocolate chips
- 1 cup peanut butter
- 1 tablespoon butter
- 1 1/2 cups crispy rice cereal
- Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13-inch baking dish.
- Mix brownie mix, oil, water, and eggs in a large bowl until smooth; spread into prepared baking dish.
- Bake in the preheated oven until a toothpick inserted into the center comes out clean, 28 to 30 minutes. Sprinkle marshmallows over brownie and continue baking until slightly melted, about 3 minutes more. Remove from oven and cool completely.
- Heat chocolate chips, peanut butter, and butter in a saucepan over low heat; cook and stir until smooth. Remove from heat and stir in rice cereal. Spread over cooled brownies. Refrigerate until firm; slice brownies to serve.