Preheat the oven to 350°F. Lightly spray a loaf pan with cooking spray and line the bottom with parchment paper. Set aside.
In a blender, pulse the oats until it turns into a fine powdery flour.
Add in the bananas, brown sugar, milk, eggs, oil, baking soda, salt and vanilla extract. Blend until smooth.
Add in the 1 cup of rolled oats and pulse 2-3 times. You don't want the oats to be too ground.
Pour the batter into the prepared loaf pan and bake in the preheated oven for 65-70 minutes, or until a toothpick inserted into the center comes out clean.