In a 1-quart microwavable bowl, microwave chocolate chips, peanut butter and butter uncovered on High 1 minute; stir. Microwave in 30 seconds increments, stirring in between, until mixture can be stirred smooth.
Stir in vanilla and pour mixture over cereal, stirring until evenly coated.
Pour mixture and powdered sugar into a large resealable bag and shake until well coated.
Spread mix onto parchment to cool. When cooled, carefully stir in M&M's, nuts and pretzel sticks.
Store in airtight container in refrigerator.
Recipe by Clever Housewife at https://cleverhousewife.com/2014/01/macadamia-puppy-chow-inspired-nut-job/