Mash a ripe banana and mix it with the nut butter and vanilla extract until smooth.
Add in the almond flour and coconut flour and mix until well incorporated.
Fold in chocolate chips. Form into cookies (mine made about 6 small ones) and place in the freezer while you make the chocolate coating.
Melt the chocolate chips and coconut oil together in your microwave or by using a double boiler.
Remove cookies from the freezer, coat them in the melted chocolate, sprinkle with flake salt if desired, and place them back in the freezer.