In a large microwave-safe bowl, combine peanut butter, chocolate chips, and butter. Microwave in 15-second bursts, stirring for 15 seconds in between, until melted and smooth. Stir in the vanilla and salt.
Pour the chocolate mixture over the cereal and gently stir until every piece is coated. Add half the coated cereal to a gallon-size resealable bag with half the powdered sugar. Seal and shake until covered. Repeat with the remaining cereal and sugar.
Spread the coated cereal into a large bowl and stir in the M&M’s and Reese’s Minis.
Notes
Storage: Store Reindeer Chow at room temperature in an airtight container. If you like it extra crisp, store it in the freezer and eat it straight from there (my fave!)