Preheat the oven to 425ºF. And line a muffin tin with 10 liners. Set aside
Prepare the flax egg by adding 1 tablespoon of flax meal with 3 tablespoons of water. Set aside for ten minutes, until a yolky consistency has formed. Melt the coconut oil over low heat and set aside.
Combine the oat flour, almond flour, baking powder, baking soda, sea salt and cinnamon to a bowl and whisk together.
In a food processor, pulse the ripe bananas until somewhat smooth. Stream in the coconut oil, vanilla, coconut sugar and the flax egg.
Add the wet ingredients to the dry ingredients. Stir until thoroughly combined (option to add in chocolate chips here if that's your thing).
Add equal amounts of the batter to 10 muffin tins. Bake at 425ºF for 5 minutes. Then turn down the oven to 350ºF for 17 minutes. Remove from the oven and let cool in the muffin pan for 10 minutes. Then transfer the muffins to a cooling rack. Let cool completely before eating. Store in a sealed container for 5 days.