Heat oven to 350degrees. Grease or spray 2 loaf pans. In a large bowl, mash bananas with a masher or by well washed hands. Dissolve soda in buttermilk-- use a larger container as it will foam up quite a bit. Mix all ingredients by hand and add in 1 cup chopped nuts. Bake at 350degrees for 1 hour, or until toothpick comes out ALMOST clean. Totally clean will mean a dryer loaf. Let cool 15 minutes after removing from oven and remove from pans. Or, let cool, cover with foil, slide into freezer bags and freeze. Great when using tin foil pans.