In large bowl, mix cereals; set aside. In small bowl, mix powdered sugar and cocoa; set aside.
In 1-quart microwavable bowl, microwave chocolate chips, peanut butter and butter uncovered on High 1 minute; stir. Microwave about 30 seconds longer or until mixture can be stirred smooth. Stir in vanilla. Pour mixture over cereal, stirring until evenly coated.
Place half of the powdered sugar mixture into 2-gallon resealable food-storage plastic bag. Add coated cereal mixture. Seal bag; shake until well coated. Add the other half of the powdered sugar mixture and shake again. Add remaining ingredients; shake to mix. Store in airtight container in refrigerator.