Just use a french vanilla cake mix only use 1 stick of butter or marg. and 2 mashed bananas.  Reduce the water by 1/4 cup and use the 3 eggs.Add in one small package of banana flavored pudding mix.  Bake in a 13x9 pan at 325 for 40-45 min or until the cake pulls away from the sides of the pan. 
Frost w/Dream whip frosting--1 pkg of dream whip/1 small pkg of banana pudding mix and 1.5 C of water. 
Dust w/ crushed vanilla wafers. If you like you can put a slice of banana on each piece of cake.  It is sooo moist. 

I know banana pudding is my favorite too.  I had 2 overripe bananas and had the stuff to make pudding, but the bananas were too far gone so I just came up w/this.  I remembered mom making pudding cakes when I was little, so I figured it would work and it did.

Banana pudding is one of my daughter's favorites. She got hooked on it visiting my sister down south. Now we make it just about every summer. I will try this recipe and see how she likes it.