1. Begin by making the Puppy Chow. To do this, heat the chocolate chips and butter in a microwave safe bowl for 1 minute. Then stir and heat an additional 30 seconds until it's melted. Be sure to be careful removing as it will be hot.
2. Place the cereal in a large bowl and pour the melted chocolate over it stirring it up and combining it well.
3. Place the chocolate covered cereal into a plastic sealed bag and toss with the powdered sugar, making sure that the cereal is well coated.
4. Place the coated cereal in a clean bowl along with the cooked popcorn and M&Ms. Stir to combine the mix and serve.