Preheat oven to 350º F. Line a muffin pan with 12 parchment paper liners and set aside.
In medium sized mixing bowl, add the dry ingredients, and whisk to combine well.
In a large bowl, add the banana, and mash.
Into the banana, add the eggs, vanilla, and coconut or almond milk. Whisk to combine.
Add the dry ingredients, and stir until just combined.
If using, fold in walnuts, chocolate chips, seeds, or pecans.
Divide the batter between the 12 muffins cups. Top each one with a thin slice of banana, if desired.
Bake Muffins for 16-20 minutes, until risen and centers are fully baked. Almond flour browns faster than other flours, so a darker golden color is normal!