Preheat the oven to 350°F (175°C) and grease a 9x5 inch loaf pan or line it with parchment paper.
In a large mixing bowl, whisk together the mashed bananas, melted coconut oil, maple syrup, egg, and vanilla extract until well combined.
In a separate medium bowl, whisk together the whole wheat flour, baking soda, salt, and cinnamon.
Add the dry ingredients to the wet ingredients and stir with a spatula until just combined, being careful not to overmix.
Gently fold in the fresh blueberries until evenly distributed through the batter.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake for 55 to 60 minutes, or until a toothpick inserted into the center of the loaf comes out clean.
Cool the bread in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.