Preheat your oven to 350°F (175°C).
Lightly grease your loaf pan.
In a bowl, mix flour, salt, and cinnamon.
In another bowl, beat butter and brown sugar.
Add eggs and vanilla. Mix well.
Stir in the mashed bananas and sour cream.
Slowly mix the wet and dry ingredients together.
Fold in walnuts, if you like.
Pour the batter into the loaf pan.
Bake for 55–60 minutes or until golden brown.
Use a toothpick to check if it’s done.
Let it cool in the pan for 10 minutes.
Move the bread to a wire rack to cool completely.