Preheat the oven to 350 degrees and grease a standard muffin pan.
In a medium bowl, whisk together the 2 cups of flour, baking soda, and salt.
In a large bowl, mix the mashed banana, eggs, milk, coconut oil, and maple syrup. Add the dry ingredients to the wet ingredients, and stir to combine.
In a small bowl, coat the blueberries with the additional tablespoon of flour. Then gently fold the blueberries into the muffin batter.
Transfer the batter to the prepared muffin pan, filling each muffin opening about 2/3 of the way. Bake the muffins for about 20 minutes, or until the tops are set and a toothpick inserted in the center of a muffin comes out clean. (It's better to undercook them a little than to overcook them.)
Cool on a wire rack. Store the muffins in an airtight container at room temperature for up to two days, or freeze them for later.