Preheat oven to 350ºF. Coat a large bread pan with oil or cooking spray.
Whisk together the water and ground flax seeds in a large bowl. Let them sit for a few minutes, until the mixture has the consistency of egg whites.
In a medium bowl, whisk together the flour, baking soda, salt, and cinnamon.
Stir the coconut milk, lemon juice, coconut oil, sugar, and bananas into the flax mixture. Slowly stir the dry ingredients into the wet mixture and fold in the blueberries.
Pour the batter into the loaf pan and place it on a baking sheet. Bake for about an hour or until a toothpick inserted into the center comes out clean; the bread will be dense and moist.
Cool for 10 minutes in the pan, then carefully remove the loaf from the pan and finish cooling on a rack.
Store tightly wrapped in the refrigerator or in the freezer for up to 2 months.
Notes
To keep the blueberries from sinking to the bottom of the loaf, gently toss them in a light dusting of flour before adding them to the batter. If you'd rather make smaller loaves, this recipe will fill 3 mini loaf pans. Bake them for 30-40 minutes.