Banana Bread

I believe this recipe came out of one of the many cookbooks mom has.  She has used this recipe as long as I can remember.

1/2 cup margarine or butter
1 cup sugar
2 eggs
1 tsp. vanilla
3 bananas
2 cups flour
1 tsp. soda
1/2 cup nuts, optional
Cream shortening and sugar until light.  Add eggs and vanilla; beat until smooth.  Add mashed bananas, flour, soda and nuts.  Bake in 2 greased and floured loaf pans at 350 degrees F for 60 minutes.  (I bake it for 30 to 40 minutes).  Can be doubled or add chocolate chips.