Prepare and grease your loaf pan and preheat your oven to 350 degrees Fahrenheit.
Prepare your egg. In a small bowl, whisk together flaxseed and water. Set aside.
Peel and put all your bananas in a large bowl. Mash with a masher or with a fork until smooth.
Stir the melted vegan butter/oil/applesauce into the mashed bananas.
Add the "egg," almond milk, and sugar and mix well until combined.
Add the flour, salt, cinnamon (if using), and baking soda. Mix gently until combined. Be careful not to overmix the batter so as not to overwork the gluten.
If batter seems too thick, add a splash of almond milk.
Fold in walnuts or other ingredients. If you want to use these as toppings, skip this step.
Pour batter into your greased loaf pan and spread evenly. If using some toppings, sprinkle them on top of the batter.
Put the pan inside the oven and bake for 50 to 55 minutes. Test doneness with a toothpick; insert one in the center of the loaf. If it comes out clean, it's ready.
Remove from the oven and let it cool in the plan for a few minutes. Transfer the bread onto a cooling rack to cool completely.