Heat oven to 350°F. Grease bottom only of 9x5- or 8x4-inch loaf pan with shortening or cooking spray. In large bowl, beat sugar and butter with spoon until light and fluffy. Stir in buttermilk and eggs until well blended.
In small bowl, mix flour, nuts, baking powder, baking soda and salt. Add to buttermilk mixture; stir just until dry ingredients are moistened. Pour into pan.
Bake 55 to 65 minutes or until toothpick inserted in center comes out clean. Cool 15 minutes; remove from pan. Cool completely, about 1 hour. Wrap tightly and store in refrigerator.