Preheat oven to 350°F. Spray bottom only of a 9x13 pan with non-stick spray and set aside.
In the bowl of your mixer, combine cake mix, pudding mix, eggs, melted butter, and chocolate chips. Blend on low speed until a thick batter forms. Spread evenly in prepared pan.
Bake for about 15 minutes, until bars are puffy and a toothpick inserted in the center comes out with fudgy crumbs.