Yields about 3 1/2 dozen cookies
1 package Duncan Hines devil's food cake mix
3/4 cup crunchy peanut butter
2-3 tbsp milk
1 cup Reese's Pieces
Preheat oven to 350°F. Line baking sheets with parchment paper; set aside.
In a large mixing bowl, combine cake mix, peanut butter, eggs and milk. Beat on low speed with electric mixer until blended. Stir in Reese's Pieces.
Roll dough into 1-inch balls and place 2 inches apart on prepared baking sheets. Press on the top of each ball to flatten slightly. Bake 10-12 minutes or until toothpick placed in center of cookie comes out clean. Cool 2 minutes on baking sheets and then transfer to cooling racks.
Source: slightly adapted from The Cake Mix Bible baking book