Preheat oven to 350 degrees F. Lightly grease, spray, or line with parchment paper an 8-inch loaf pan. Set aside.
In a bowl, mix the flour, baking powder, baking soda, salt, and cinnamon.
In a second large bowl, whisk together coconut milk, sugar, chia seed egg, and mashed bananas.
Add the wet ingredients to the dry ingredients and mix together with a spatula until combined. Fold in walnuts.
Pour banana bread mix into the prepared loaf pan. Bake for 50-60 minutes. Cool for 10 minutes, transfer to a metal rack to cool for another 30 minutes.
Notes
To make chia "egg" stir together 1 tablespoon of chia seeds and 3 tablespoons of water. Allow to gel up for at least 5 minutes. Stir again.
I used a standard-size loaf pan, which is about 9x5.
There is some wiggle room for the additions. I used 1 cup of walnuts, but you can choose to omit nuts or even chocolate chips.
To store this bread, first, allow it to completely cool. Then, wrap with plastic wrap. It'll keep for up to 3 days on the counter and up to 5 days in the refrigerator.