Preheat your oven to 350 degrees F (175 degrees C). Grease a 9×5 inch loaf pan.
In a large bowl, mix the melted butter and sugar. Add the eggs and vanilla extract, combining well.
In a separate bowl, blend together the flour, baking soda, and salt.
Gradually stir the dry ingredients into the butter mixture until smooth.
Gently fold in the sour cream, walnuts, and sliced bananas.
Pour the batter evenly into the prepared loaf pan.
