Preheat oven to 350ºF and line a muffin tin with liners.
In a large bowl, whisk together the flour, baking powder, baking soda, and sea salt. In a blender, add the egg, maple syrup, almond milk, coconut oil, vanilla, and spinach. Process until pureed.
Add the spinach mixture to the flour mixture and stir until just combined. Fold the mashed bananas into the green mixture. Fill the muffin cups about 3/4 full with batter. Bake for 25 minutes or until a toothpick inserted in the center comes out clean. Store at room temperature for 3 days or freeze. And, you can serve them with Coconut Whipped Cream for that little extra something if you like!