Preheat oven to 350 F. Line a muffin pan with silicone muffin cups (or use paper liners).
Add all dry ingredients to a large mixing bowl and mix until combine.
In a blender or food processor, blend the coconut oil, apple sauce, maple syrup, milk, banana, spinach, egg, and vanilla extract until completely pureed.
Add the wet ingredients to the dry ingredients, and fold together gently until just combined. (Do not over mix.)
Evenly divide the batter into the 20 muffins cups, filling about 3/4 of the way full. Bake for 21-25 minutes, or until inserted tooth pick comes out clean. The muffins should be firm to the touch on top, but not quite browning. Allow to cool for several minutes before serving.