Preheat oven to 325°F. Spray a standard muffin tin with cooking spray.

Combine the oil, maple syrup, eggs, milk, and vanilla in a large mixing bowl and whisk until well combined. Stir in the bananas. Add the flour, baking soda, and salt, and stir well.

Crumble the cookies, reserve a handful of cookie crumbles, and fold the rest into the batter.

Divide the batter evenly among the muffin cups. Sprinkle the reserved cookie crumbles on top of each muffin. Bake for 25 - 30 minutes or until a toothpick inserted into the center comes out clean.

Let cool in the pan for 10 minutes.