Gather all ingredients.
Combine all cereals in a large bowl; set aside.
Place chocolate chips, peanut butter, and butter in a 1-quart microwave-safe bowl. Microwave, uncovered, on high for 1 minute, then stir. Continue warming mixture until smooth and combined, about 30 seconds longer. Stir in vanilla.
Pour chocolate mixture over cereal and stir until evenly coated. Transfer to a 2-gallon resealable plastic bag.
Add powdered sugar to the bag and seal; shake until well-coated.
Evenly spread cereal out onto waxed paper to cool.
