The chocolate version is basically the recipe Elle posted (I use coconut flour instead of almond, though) and as much cocoa as you like (I used about 2 tsp.) Bake as usual.

The "buttercream" frosting is this:

Melt 2 T butter (I used salted)
Stir in 1 T cocoa powder, about 8 drops Sweetzfree, and about 1T of heavy cream. Put in the fridge for a bit to "set up", but not solidify. Take it out, and use either a handmixer or balloon whisk on a KitchenAid, and let it go and whip until fluffy. Frost the cookies with it.