Preheat oven to 325 degrees F. Grease and flour an 8 1/2 by 4 1/2 inch or a 9x5 inch loaf pan.
In a large bowl, whisk together flour, baking soda, salt and sugar. For best results, whisk for at least a minute to ensure all of the ingredients are thoroughly blended.
In a mixing bowl, mash the bananas, then add the eggs, oil, buttermilk and vanilla.
Add flour mixture to banana mixture and stir until combined. Fold in nuts.
Pour into loaf pan. Bake at 325° for 1-1/4 to 1-1/2 hours or until a toothpick comes out clean. Cool on wire rack.