Combine margarine, bananas, and sugar.
Add eggs, one at a time, beating well.
Sift flour, salt, and soda.
Add dry ingredients alternately with buttermilk to batter. Mix well.
Stir in nuts and vanilla.
Pour into 2 greased and floured loaf pans.
Bake at 325 degrees for 75 to 80 minutes or until pick inserted in center comes out clean (22 minutes for mini loaves.) Freezes well and makes a nice gift!
Optional:
Mix 1 1/2 tsp sugar & 1 1/2 tsp cinnamon together and sprinkle over top of loaves.