Preheat oven to 350 degrees F. Coat an 8x4-inch loaf pan with cooking spray.
In a medium sized bowl, mash the bananas. Add the chia eggs, oil, and vanilla to the mashed bananas, mixing till well incorporated.
Next, add the flour, sugar, baking soda, baking powder, salt, and cinnamon. Mix till just combined, being careful not to overmix. A few lumps are okay. If the batter seems too stiff, add a little plant milk (like almond or oat) to thin it out.
Pour the batter into your greased loaf pan.
Bake for about 40-50 minutes, or till a toothpick inserted in the center comes out clean.
Let cool for at least 15 minutes before slicing and serving.