Preheat the oven to 350 degrees F (175 degrees C). Line a muffin tin with paper liners.
Place mashed bananas, maple syrup, eggs, olive oil, and milk in a medium-sized bowl; mix until well combined. Add oats, whole wheat flour, oat flour, baking soda, vanilla extract, salt, and cinnamon and mix well.
Place pecans in a food processor or blender and pulse until ground. Add ground pecans to the batter. Pour approximately 1/3 cup batter into each muffin cup.
Bake in the preheated oven until the top of a muffin springs back when pressed, about 20 minutes.
