Combine chocolate chips and peanut butter in an 8 cup glass measure. Microwave on High for 1-1/2 minutes until melted; stir in nuts. Spread half of mixture in a 13x9" pan. Combine cherry frosting and marshmallow cream in a mixing bowl. Spread on top of chocolate mixture. Top with remaining chocolate mixture. Chill several hours until firm. Cut into 1-1/2" squares