Preheat the oven: Preheat your oven to 350°F (175°C). Line a muffin tin with paper liners or lightly grease the cups.

Prepare the chia egg: In a small bowl, mix the chia seeds with 6 tablespoons of water and let it sit for about 5 minutes until it forms a gel-like consistency.

Mix wet ingredients: In a large mixing bowl, combine the mashed bananas, maple syrup or agave nectar, melted coconut oil, vanilla extract, chia egg, and almond milk. Mix well until everything is evenly combined.

Combine dry ingredients: In another bowl, whisk together the almond flour, oat flour, baking powder, baking soda, and salt.

Combine wet and dry ingredients: Gradually add the dry ingredients to the wet ingredients, stirring until just combined. Be careful not to overmix.

Add optional ingredients: If you're adding nuts, chocolate chips, or dried fruit, fold them into the batter at this point.

Fill muffin cups: Spoon the batter into the prepared muffin tin, filling each cup about ⅔ full.

Bake: Bake in the preheated oven for 20-25 minutes, or until the tops are golden brown and a toothpick inserted into the center comes out clean.

Cool and serve: Allow the muffins to cool in the tin for a few minutes before transferring them to a wire rack to cool completely. Enjoy your delicious vegan banana almond-oat flour muffins!