I credit Pinterest for this one. It was a huge success!! We loved it, and I don't think I'll make banana bread any other way now.
1 yellow cake mix
3 large ripe bananas
(I added 1 tsp. vanilla, 1 tsp. cinnamon and 1 c. mini chocolate chips)
Pour into two (sprayed) medium pans and bake at 350 for 35-40 min.