Line a muffin tin with 12 baking cup liners and set aside. (You can grease the muffin tin well instead of using liners)
Beat mashed banana, eggs, vanilla, maple syrup, and oil together until blended.
Add almond flour, flax meal, baking soda, baking powder, salt, cinnamon, and nutmeg and stir until just mixed together. Stir in chocolate chips and/or nuts if using them.
Pour batter into muffin tin, evenly distributing between the 12 spaces.
Place in oven and bake for about 25 minutes or until toothpick inserted into the center comes out mostly clean (check at 23 minutes to make sure you don't over bake).
Remove from oven and let sit in pan for 10 minutes before removing and letting muffins finish cooling on a wire baking rack.
Eat fresh and store any leftover muffins in an airtight container on the counter for three days or in the refrigerator for up to five days.
Notes
* To freeze, place muffins in a freezer safe bag and freeze for up to 3 months. Defrost in the refrigerator overnight or microwave for 30-60 seconds. If microwaving, don't over heat and eat right away or the muffin texture will be tough.*To make as bread, bake for about 50 minutes in a loaf pan. Cool for 10 minutes and then remove from pan by running a butter knife around the edge and then using a flat, wide spatula to lift from the bottom if it doesn't come right out or starts to fall apart.