In a large bowl, mash the bananas. In a small microwave-safe bowl, melt the coconut oil, but be careful not to heat. Add to the mashed bananas along with the light brown sugar, honey, and eggs. Whisk to combine.
In a medium bowl, whisk together flours, baking soda and salt.
Add dry ingredients to the wet ingredients; stir just until combined. Gently fold in the fresh or frozen blueberries.
Spoon batter into prepared muffin tin and sprinkle tops with turbinado sugar. Bake for 15 minutes until a toothpick comes out clean.