Heat oven to 375 F. Line a baking sheet with parchment paper.
In a bowl mix the flour, baking soda, baking powder, sea salt and ground nutmeg, and stir to combine. Set aside.
In a mixer with a paddle attachment, cream the coconut oil, sugar and vanilla until light and fluffy. Add the banana and cream until well combined. Slowly add the dry ingredients and mix until just combined.
For the topping: Combine the remaining ingredients in a small bowl.
Scoop the batter into 2-tablespoon serving sizes, and roll them in the topping mixture. Spread the cookies out on the baking sheet and gently press to flatten them slightly. Bake for 5 to 7 minutes, or until lightly golden on the outside. Do not overbake. Cookies should be slightly underbaked in the center.