Preheat Oven to 350 degrees
In a medium mixing bowl, add banana and mash really well
To the bowl, add your egg, oil, almond milk, honey and vanilla
In another mixing bowl, add your cinnamon oat flour, baking powder, cinnamon, and salt
Next add your wet ingredients to your dry ingredients and add the walnuts then mix well
Once your mixture is fully combined, line a muffin tin with muffin cups and spray with some spray oil.
Next, fill your muffin cups 3/4 of the way full and transfer to the oven.
Bake for 15 - 17 minutes or until the muffins come clean when pierced with a toothpick
Once baked through, remove from oven and allow to cool for 5 minutes