As a child this was and still is my favorite cake, it is a really moist and tasty cake as well, ok lets get started, I assume that everyone knows that all ingredients should be at room temperature.

pound butter
4 eggs
1-1/2 cups sugar
1 cup sour cream
cup mashed ripe bananas
1 teaspoon baking powder
1 teaspoon baking soda
1 teaspoon vanilla
3 cups flour

Cream your butter and sugar together then add your bananas and mix until smooth add your eggs one at a time now add your sour cream, baking soda, baking powder, vanilla, and flour, mix on low speed for 1 minute and then on 2nd speed for about 2 minutes or until smooth.
Place your cake mix in a well greased and floured 10 inch x 3 inch tube pan and let bake in a preheated 350 degree oven for about 25 to 35 minutes, test cake by inserting a pick in the center and if it comes out clean then it is done.

Icing on the cake:

4 tablespoons flour
1 cup milk
add the flour to the cold milk and stir with a wire whisk and then cook it on the stove until it is thick, remove from stove without burning it and let it cool.

In a mixing bowl add cup butter, cup shortening, 1 cup granulated sugar, 1 teaspoon vanilla, mix all for 1 minute then add the mixture that you cooked and mix for 2 or 3 minutes or until it is as fluffy as you desire, using a paddle on your mixer and not the whip.