Place oven to the lowest position.  Heat oven to 350 degrees.  Grease the bottoms only of 2 loaf pans.  Mix sugar and butter ina large bowl.  Stir in the eggs until well blended.  Add bananas, buttermilk, and vanilla.  Beat until smooth.  Stir in the remaining ingredients except nuts just until moist.  Stir in the nuts.  Pour batter into the pans.  Bake about 1 hour or until golden brown and a pick comes out clean.  Cool 5 minutes.  Loosen sides of loafs from the pan to remove.  Cool completely before slicing.  Wrap tighly and store at room temperature.