Spinach Muffins for Picky Eaters (Gluten-free!)

ripe banana ((6 to 8 ounces))

water

almond butter ((or any other nut/seed butter))

egg ((or a vegan flax/chia egg; see note))

honey

fresh baby spinach (, loosely packed )

rolled oats ((certified gluten-free, if needed))

baking soda

ground cinnamon ((optional))

vanilla extract

salt