Place cereal in a large bowl and set aside.
In a medium saucepan over low heat, combine chocolate chips, peanut butter, and butter and cook, stirring frequently, until melted.
Remove from the heat and stir in vanilla.
Pour mixture over cereal, stirring until evenly coated.
Pour into a 2-gallon resealable plastic bag. Add powdered sugar. Seal bag and shake until well coated.
Spread out on a piece of waxed paper to cool, then serve immediately or transfer to an airtight container to store. \ENJOY