Place cereal in a large mixing bowl. Prepare a baking sheet with parchment paper.
In a microwave-safe bowl melt semi-sweet chocolate chips, creamy peanut butter, unsalted butter, and peppermint extract. Heat for 30 seconds at a time mixing in between until melted and smooth.
Pour melted chocolate over cereal and toss to coat. Gently mix to coat.
Add in powdered sugar and again gently mix to coat. Place in your prepared baking sheet to dry and add in Mint Chocolate M&Ms. Serve and enjoy.
You can keep the puppy chow in an airtight container for up to 1 week.