Preheat oven to 350 degrees.
Cream butter and sugar with mixer.
Add bananas and mix well.
Add eggs and continue mixing.
Dissolve soda in sour cream, then add to mixture.
Add flour and salt and mix well.
Optional, fold in nuts and/or chocolate chips.
Bake into a well-greased loaf and floured pan at 350º for 1 hour.