||Preheat oven to 325 degrees. Grease and flour a 9-by-5-by-2 inch loaf pan. Cream butter and sugar well. Blend in bananas, eggs and vanilla. In a separate bowl, sift together flour, baking soda and salt. Add the dry ingredients to the banana mixture, alternating with the buttermilk and mixing well after each addition. Add the nuts, and mix just to combine. Pour batter into prepared loaf pan. Bake at 325 for 1 1/4 hours or until a toothpick comes out clean when inserted in the center of the loaf.