Combine banana and sour cream. Set aside.
In a large bowl, cream together the margarine and sugar until smooth. Beat in the eggs one at a time, then stir in the vanilla and banana mixture.
Combine the flour, baking soda, baking powder and salt; stir into the banana mixture.
Spread the batter evenly into the prepared pan or pans.
Bake for 50 minutes in the preheated oven, or until a toothpick inserted into the center of the bread comes out clean. If bread begins to brown too much, place a piece of aluminum foil on top - do not seal around pan.
Time to Prepare: 10 minutes prep, 50 minutes bake
Submitted By: Cheryl
Original Source: www.allrecipes.com - but with several changes