Cream butter. Add sugar gradually. Cream well. Blend in bananas, eggs and vanilla. Sift together flour, salt and soda. Add dry ingredients alternately with buttermilk. Blend until just combined. Fold in nuts. Bake in greased pan at 350° for 1 ½ hours.
For mini loaf pan, bake 45 minutes. Use powdered buttermilk. Make for grandpa at Christmas.