Prep work: Preheat oven to 350F. Line a loaf pan with parchment paper (you can leave a bit of overhang on the sides for easy removal), or lightly grease it.
Combine dry ingredients: In a large bowl, mix together the flour, cinnamon, baking powder, baking soda, and salt.
Combine wet ingredients: In a separate large bowl, mash the bananas with a fork until mostly smooth (a few small lumps are fine). Whisk in the maple syrup, almond butter, applesauce, vanilla, and nondairy milk until well combined.
Bring it all together: Pour the wet mixture into the dry mixture and gently fold together until just combined (do not overmix). Stir in walnuts and/or chocolate chips, if using.
Bake: Pour the batter into the prepared loaf pan. Bake for 40-45 minutes, or until a toothpick inserted into the center comes out clean. Remove from the oven and allow to cool for 5-10 minutes in the loaf pan, then transfer to a wire rack to cool completely before slicing. Serve and enjoy!