In a large microwave-safe bowl, combine the marshmallows, peanut butter, chocolate chips and butter. Cover and microwave on high for 1-1/2 minutes. Stir until well blended (the mixture will be lumpy). Add cereal and peanuts; stir until well coated. Spread into a greased 13-in. x 9-in. pan.
For the frosting, combine chocolate chips, butter and milk in another microwave-safe bowl. Cover and microwave on high for 1 minute. Add sugar and vanilla. With an electric mixer, beat frosting until smooth. Spread over the cereal mixture. Cover and refrigerate for 2 hours or until firm. Cut into squares.
Notes
Crispy Chocolate Squares
Folks will think you slaved away on these fast and fudgy treats. People often request the recipe and are surprised to find out how easy they are to make. Even kids can make 'em! —Karen Speidel, Wheeling, Illinois