01 - Add Chex cereal to a large mixing bowl and set aside.
02 - In a microwave-safe bowl, combine chocolate chips, peanut butter, and unsalted butter. Microwave in 30-second intervals, stirring thoroughly after each, until fully melted and smooth, approximately 1 to 2 minutes.
03 - Stir pure vanilla extract into the melted chocolate and peanut butter mixture until integrated.
04 - Pour the chocolate-peanut butter mixture over the Chex cereal. Fold gently with a spatula until every piece is evenly coated.
05 - Transfer the coated cereal into a large zip-top bag. Add powdered sugar, seal, and shake vigorously until all pieces are evenly covered.
06 - Spread the sugar-coated cereal mixture onto a parchment-lined baking sheet and allow to cool for 10 minutes.
07 - Fold in M&M’s, pretzels, mini marshmallows, and red and green sprinkles, mixing until the snack mix is evenly distributed.
08 - Store the finished snack mix in an airtight container at room temperature for up to 1 week.