1 (18.25 ounce) package white cake mix
1/3 cup vegetable oil
8 ounces sour cream
8 tablespoons unsweetened cocoa powder
1/2 cup semisweet chocolate chips
1 banana, peeled and mashed
Preheat oven to 350 degrees F (175 degrees C). Lightly grease and flour one 9×13 inch pan.
Mix together cake mix, oil, eggs, sour cream, cocoa, chocolate chips, and banana, and beat for two minutes. Pour into prepared pan.
Bake at 350 degrees F (175 degrees C) for 35 minutes. Let cool in pan and dust with powdered sugar if desired. ENJOY!