Crispy Peanut Butter Brownies

Preheat the oven to 350. Grease a 9x13 pan. Mix and bake brownies according to box instructions. Take brownies from oven and sprinkle entire bag of marshmallows on top. Return brownies to the oven for 3 minutes. Melt chocolate chips, peanut butter, and butter in a medium saucepan. Cook on low until chocolate is melted, stirring constantly. Add rice cereal. Spread over marshmallows, swirling the chocolate mixture and the marshmallows as you go. Chill bars in the refrigerator until completely cool, otherwise they are way to sticky to cut.