Preheat oven to 325�F. Cream butter and sugar together thoroughly. Blend in bananas, eggs and vanilla. Sift flour, baking soda and salt together. Add to banana mixture, alternating with buttermilk and mixing thoroughly after each addition. Add nuts and gently mix. Pour batter into greased and floured loaf pan. Bake for 1 1/4 hours, or until done.
Yields 1 loaf.