In a large mixing bowl, combine all dry ingredients: oat flour, whole wheat pastry flour, baking powder, sea salt, cinnamon.
Blend milk and spinach in a food processor until no spinach pieces are visible and you’re left with green milk.
Mash the banana with a fork.
Combine all wet ingredients in a separate bowl: spinach/milk mixture, egg, mashed banana, butter or coconut oil, and vanilla.
Pour the wet ingredients over the dry ingredients and combine. Batter should be thick.
Heat a pan over medium heat. Add a little bit of butter or coconut oil to the pan.
Add ~ 3 tbsp of batter to the pan. Cook for about 3 minutes, or until bubbles form on the surface.
Flip and continue for ~ 2 minutes on the other side.