01 -
Preheat oven to 325°F (165°C) and generously grease two loaf pans approximately 8 1/2 x 4 1/2 inches in size.
02 -
Cream the softened butter and white sugar in a large mixing bowl until well combined.
03 -
Add the eggs and mix thoroughly. Stir in the mashed bananas, sour cream, and vanilla extract until smooth.
04 -
Add the flour, cinnamon, baking soda, and salt to the wet mixture. Stir until just combined. Fold in the walnuts if using.
05 -
Divide the batter evenly between the prepared loaf pans. Bake for 1 hour or until a toothpick inserted in the center comes out clean.