Preheat the oven to 350 F. In a large bowl, mix together cake mix, pumpkin puree, eggs, and vegetable oil until smooth. Fold in the M&Ms. In a shallow dish, combine granulated sugar and ground cinnamon.
Roll cookies into balls and roll in the cinnamon sugar mixture. Place onto a large ungreased baking sheet at least 2-inches apart. Bake for 10-12 minutes.