Preheat oven to 300?. Grease 4 loaf pans & dust lightly with a cinnamon & sugar mixture. Cream butter & sugar. Mix in eggs, mashed bananas, sour cream, vanilla & cinnamon. Add salt, baking soda & flour & mix well. Stir in nuts. Divide into prepared pans. Bake for 1 hour or until toothpick comes out clean.