Place cereal in a huge bowl.
In a microwavable bowl, microwave chocolate chips, peanut butter and butter uncovered on High 1 minute.
Keep microwaving until smooth.
Pour this over the cereal and stir to coat.
Pour cereal into 2-gallon ziploc bag.
Sprinkle in powdered sugar
Seal bag and shake, shake, shake!
Spread cereal on wax/parchment paper to cool.
Add mini Reese's candies