In a large microwave-safe bowl, melt chocolate at HIGH for 1 minute. Stir and heat an additional 30 seconds at HIGH or until melted. Stir in peanut butter until melted. Gently stir cereal into chocolate-peanut butter mixture, until well coated. Place confectioner''s sugar in 2-gallon storage bag. Add coated cereal to sugar and close bag. Gently toss cereal mixture until well coated. Store in airtight container in refrigerator.