Preheat the oven to 350 degrees.

Spray a 9 x 5 loaf pan with cooking spray and set aside.

In large bowl combine the mashed bananas, melted butter, sugar, egg, and vanilla. Mix well to combine.

In a medium bowl combine the flour, baking soda, and salt.

Add the dry ingredients to the wet ingredients and mix until just combined.

In another small bowl combine the brown sugar and cinnamon.

Pour half of the banana bread mixture into the prepared pan. Sprinkle half of the cinnamon sugar mixture over top of the batter in the pan. Carefully pour the remaining banana bread batter over top of the sugar mixture.

Add the oats to the remaining cinnamon sugar mixture and mix well. Sprinkle over top of the bread.

Bake for 60-65 minutes or until golden brown and baked through. Remove from oven and cool for 10 minutes.

Run a knife around the edges of the pan and remove the bread from the pan. Cool completely on a wire cooling rack.