In a small bowl, microwave white chocolate chips for 30 seconds, stir. Microwave for additional 30 second increments until chips are melted and smooth. Pour chocolate over cereal and stir carefully to fully cover but not break the cereal. Pour cereal mixture into a large gallon size plastic bag (or, continue in the same bowl you're using).
In a separate bowl, combine cinnamon and granulated sugar. Pour over cereal mixture, close bag, and shake to coat. Add powdered sugar, close bag, and shake to evenly coat cereal (or, stir until evenly coated, if using a bowl).
Line a baking sheet with parchment or wax paper and pour cereal mixture into a single layer. Refrigerate for 10-15 minutes (or until chocolate has hardened). Store in an airtight container until ready to serve.
It should go without saying, but this snack mix is meant for human consumption only and is not made for dogs.
Optional mix-ins. Try adding 1 cup of mix-ins for every 4 cups of cereal used: pretzels, m&m's candies, nuts, cookie pieces, mini marshmallows, or graham cracker pieces.
For a large party, try doubling or tripling this recipe.