Preheat oven to 350°F (177°C). Line an 8 inch by 8 inch baking pan with parchment paper, leaving some overhang for easy removal later.

Add mashed bananas, quick oats and maple syrup to a large mixing bowl. Mix with a spatula until everything is evenly combined.

Divide the oat mixture in half. Add one half of it to your prepared baking pan and use your hands to spread and press it evenly across the bottom.

Add blueberries to a small high powered blender and blend until the blueberries become a thick liquid.

Carefully pour the blueberry puree over the oat mixture and use a spatula to spread it evenly.

Place the remaining half of the oat mixture on parchment paper and shape it into a thin square to create the topping.

Gently place the oat mixture crust pieces on top of the blueberry puree and press together any cracks.

Bake for about 30 minutes or until the oats on the surface are golden brown.

Let bars cool fully before removing from the pan and cutting.