So so rich and moist. Absolutely delicious. I made this as I would my pumpkin bars but used banana's instead of canned pumpkin. I used Larinda's trick to ripen my banana's in the oven for 1 hour. Worked perfect. Thanks Larinda. Just to warn you, this is a very rich and sweet cake. Small pieces will go far.
Preheat the oven to 350 degrees. In a medium bowl, whisk together the flour, baking soda, cinnamon, and salt.
In a mixer beat together the butter and sugars. Beat in the eggs one at a time. Mix in the vanilla and mashed bananas.
Mix in half of the flour mixture, then the sour cream, then the other half of the flour mixture.
Spread batter evenly in a greased 10x15 baking pan. Bake at 350 degrees for 20 minutes, or until toothpick inserted in the middle comes out clean. Cool completely before frosting. I was being lazy and bought store brand frosting but feel free to make your own.