Preheat the oven to 350° F. Grease three 9x15 bread loaf pans with cooking spray, shortening, or butter.

Put the bread flour, baking soda, baking powder, cinnamon, and salt in a medium bowl. Whisk them until you combine them. NOTE: If you don't have bread flour, you can use all-purpose, but your finished loaf will have a slightly denser texture.

Peel the bananas put them into a large mixing bowl, and mash them until they are relatively smooth. Add the sugar, egg, melted butter, and vanilla extract. Mix these together.

Slowly add in the bowl of dry ingredients. You want to stop when everything is combined.

Stir in the chopped walnuts.

Pour the banana bread batter into the three prepared bread pans, splitting the contents evenly.

Bake the bread for one hour. Sides will pull slightly away from the pans. Test by inserting a toothpick - it should come out clean.

After you remove the loaves from your oven, let them cool in the pan for ten minutes. Firmly, quickly flip the bread out onto a cooling rack. After it cools completely.