Preheat the oven to 350 F. In a large bowl, mix together cake mix, peanut butter, eggs, and vegetable oil until smooth. Fold in the peanut butter cups.
In a shallow dish, combine granulated sugar and ground cinnamon. Roll the cookie dough into balls, and roll into the cinnamon sugar mixture. Place the cookies onto a large ungreased baking sheet. Bake for 10-12 minutes.