In a large saucepan, melt butter over low heat. Stir in marshmallows and peanut butter; cook, stirring frequently, until melted, about 8 minutes. Stir in cereals until coated. Remove from heat.
Using a spatula coated with cooking spray, press mixture into prepared pan. Let cool for 1 hour. Cut into bars. Store in an airtight container for up to 3 days.
Notes
*We used Chocolate Cheerios and Cap’n Crunch’s Peanut Butter Crunch.
Recipe by Paula Deen Magazine at https://pauladeenmagazine.com/peanut-butter-chocolate-cereal-bars/