Preheat your oven to 350℉. Line an 8-inch or 9-inch loaf pan with parchment paper for easier bread removal.
In a large mixing bowl, mash bananas with a fork or a potato masher.
Add melted coconut oil, brown sugar, granulated sugar, and vanilla and whisk to combine.
In a separate bowl, add your dry ingredients: all purpose flour, oat flour, baking soda, cinnamon, and salt and mix to combine.
Add the dry ingredients into the banana mixture and stir with a spoon (do not whisk) until just combined and no flour pockets remain. Do not over mix or your banana bread will turn out tough. If batter is too dry, add 1-2 tbsp of dairy-free milk as needed.
Optional step: Add your optional ½ cup of add-ons and fold until well distributed. Do not over mix the batter.
Pour batter into the lined loaf pan. Sprinkle 2 tbsp of brown sugar on the surface of the loaf before baking.
Place in the oven and bake for 50-55 minutes or until a toothpick inserted to the center comes out clean. Let cool for at least 15 minutes before removing from the loaf.