Preheat the oven to 350F and line a standard muffin tin with 6 baking cups. (In my experience, these silicone cups work best.) In a medium mixing bowl, mash the bananas with a fork until they resemble a relatively smooth puree. Stir in the egg, then add the coconut flour, cinnamon, and baking soda. Mix well, until a thick and uniform batter is created.

Spoon the batter into the prepared baking cups, then bake at 350F for 25-30 minutes, until the centers are firm. Allow to cool completely before serving. Store in a sealed container in the fridge for up to one week, or in the freezer for up to two months.