Grease bottoms only of 10 (4 1/2x2 1/2x1 1/2-inch) mini loaf pans with shortening or cooking spray.
In large bowl, mix sugar and butter with spoon. Stir in eggs until well blended. Add bananas, buttermilk and vanilla; beat until smooth. Stir in flour, baking soda and salt just until moistened. Stir in nuts.
Divide batter evenly among pans, filling each with about 1/2 cup batter.
Bake 30 to 35 minutes or until toothpick inserted in centers comes out clean. Cool 5 minutes.
Loosen sides of loaves from pans; remove from pans to cooling racks. Cool completely, about 2 hours.
Wrap tightly and store at room temperature up to 4 days, or refrigerate up to 10 days.