This cake has been remade, updated, recipe changed and in general made much better here!  
This Banana Cake is AWESOME! So incredibly moist! I first had this cake at an engagement party, and loved it so much I was asking the woman who made it for the recipe. She said she found it online somewhere but did not have the recipe. I was immediately disappointed because it was so phenomenal. But, then she gave me a little tip and said you cook it for 1 hour at 275 degrees and then you immediately put it in the freezer for 45 minutes. I knew with these too abnormal instructions I would be able to find the cake with my trusty Google! And I did! And when my family came in town I knew it was the perfect occasion to make it! Boy, was it good! Just as moist and delicious as I remembered. If you like bananas and cake…this one is for you!

You will need:
3/4 cup butter
2 1/8 cups white sugar
3 eggs
2 teaspoons vanilla extract
3 cups all-purpose flour
1 1/2 teaspoons baking soda
1/4 teaspoon salt
1 cup milk
1/2 cup sour cream
2 teaspoons lemon juice
1/2 cups mashed bananas

For the frosting:
1/2 cup butter, softened
1 (8 ounce) package cream cheese, softened
3 1/2 cups confectioners’ sugar
1 teaspoon vanilla extract

Preheat oven to 275 degrees F (135 degrees C). Grease and flour a 9×13 inch pan. In a small bowl, mix mashed bananas with lemon juice, set aside. In a medium bowl, mix flour, baking soda and salt. Set aside. In a large bowl, cream 3/4 cup butter and 2 1/8 cups sugar until light and fluffy. Beat in the eggs one at a time, then stir in 2 teaspoons vanilla and the sour cream. Beat in the flour mixture alternately with the milk. Stir in banana mixture. Pour batter into prepared pan. Bake in preheated oven for 1 hour, or until a toothpick inserted into the center of the cake comes out clean. Remove from oven and place directly into freezer for 45 minutes. This will make the cake very moist.

For the frosting: In a large bowl, cream 1/2 cup butter and cream cheese until smooth. Beat in 1 teaspoon vanilla. Add confectioners sugar and beat on low speed until combined, then on high until frosting is smooth. Spread on cooled cake.

Source: Adapted from