Preheat oven to 325 degrees F and generously grease two loaf pans that are approximately 8 1/2 x 4 1/2 inches in size.
Cream butter and sugar in a large bowl. Add the eggs and mix well. Add sour cream, mashed bananas, vanilla and stir to combine. Add the flour, salt, cinnamon and baking soda to the wet ingredients and stir until just combined. Fold in the walnuts, if using.
Divide the batter evenly between prepared loaf pans. Bake for 1 hour or until a toothpick inserted in the center comes out clean.
If using smaller bananas, 5 are recommended.
The more ripe your bananas are, the better the bread will be!
Calories: 292kcal | Carbohydrates: 43g | Protein: 5g | Fat: 12g | Saturated Fat: 5g | Cholesterol: 38mg | Sodium: 284mg | Potassium: 203mg | Fiber: 2g | Sugar: 24g | Vitamin A: 259IU | Vitamin C: 3mg | Calcium: 33mg | Iron: 1mg