Coat an 8" square pan with vegetable cooking spray. Put peanut butter, chocolate chips and butter in a 3-qt. microwave safe bowl. Microwave uncovered on high for 2 to 2 1/2 minutes until butter melts and chocolate chips look soft and glossy but still retain their shape. Stir utnil smooth, then stir in marshmallows. Microwave on high for 45 to 60 seconds. Marshmallows will be slightly melted. Stir to mix, then stir in cereal until well blended. Scrape into prepared pan; spread evenly. Refrigerate 2 to 3 hours until firm. Cut into 1 1/2 inch squares. Makes about 25 squares. Recipe by: Womans Day/June 1988 Posted to recipelu-digest Volume 01 Number 662 by "Diane Geary." on Jan 31, 1998