Chocolate Banana Cake

1 (18.25 ounce) box devil's food cake mix
1 cup mashed ripe bananas
1/3 cup vegetable oil
3 eggs

Preheat oven to 350 degrees F. Grease and flour a 13 x 9-inch pan.

Beat cake mix, mashed bananas, oil and eggs with an electric mixer on low speed for 30 seconds. Increase speed to medium and beat for 2 more minutes. Pour the batter into the prepared pan.

Bake for 33 to 36 minutes or until a wooden pick inserted near the center comes out clean. Let cake cool then frost with your choice of frosting, if desired.