Preheat oven to 350 degrees. Lightly spray one 9×5 bread pan* with cooking spray. Mix bananas, sugar, butter, eggs, vanilla, and cinnamon together in a medium sized bowl.
In a separate bowl combine baking soda, salt, and flours. Gently mix dry ingredients into wet ingredients until just combined. Pour batter into bread pan. Sprinkle cinnamon sugar mixture on top. Bake for 45-50 minutes.