Preheat your oven to 375F. Prepare a 12-cavity muffin pan with liners and set aside.
Combine in medium bowl, the flour, salt, cinnamon, nutmeg, baking powder, and baking soda. Mix very well with a whisk or fork.
2 cups All Purpose Flour, 1 teaspoon Cinnamon, ½ teaspoon Nutmeg, 1½ teaspoon Baking Powder, ½ teaspoon Baking Soda, ¼ teaspoon Salt
Place in the jar of a blender, the bananas, eggs, milk, brown sugar, vanilla, and spinach. Blend until smooth.
1 cup Very Ripe Bananas, 2 large Eggs, ½ cup Brown Sugar, ½ cup Milk, 1 teaspoon Vanilla Extract, 4 oz Baby Spinach
Pour the wet ingredients into a large bowl. Add the dry ingredients to the wet ingredients. Whisk until just combine, without over mixing.
Divide the batter equally into the prepared muffin pan cavities.
Bake into the preheated 375F oven for 15 minutes or until a toothpick inserted in the middle comes out clean.