Preheat oven to 350°F. Coat a 9×12-inch baking dish with nonstick spray and set aside.
In a large bowl, combine the chocolate cake mix, instant chocolate pudding mix, and milk. Mix until well combined. Then, stir in the peanut butter until the batter is smooth.
Gently fold in the chocolate chips and chopped peanut butter cups.
Pour the batter into your prepared baking pan. Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
Let the cake cool slightly before serving.
Follow along to learn more how to make this easy fudgy peanut butter cup dump cake.