Preheat the oven to 350ºF and line a 9-inch by 5-inch loaf pan with parchment paper.
In a large bowl, mash the bananas with a fork. Add in the coconut flour, eggs, coconut sugar, cinnamon, baking soda, baking powder, salt, and vanilla. Use a whisk to stir the batter well, breaking up any lumps so a smooth batter is formed. (You can also use an electric hand mixer to do this.)
Pour the batter into the lined loaf pan and bake until the center of the loaf has risen and started to crack, feeling firm to the touch, about 45 to 55 minutes. Cool completely before slicing and serving.
Because this loaf is moist, be sure to store it in an airtight container in the fridge for best shelf life. It should last at least a week when stored in the fridge, though you might eat it all before then!