In a large bowl, combine almond flour, cocao powder, sweetener, baking powder and salt. Add in egg, butter and vanilla extract and stir well until dough comes together.
Roll out dough between two pieces of parchment paper to desired thickness, but no more than 1/4 inch thick. Lift off top piece of parchment and set aside.
Using a 2-inch diameter cookie cutter, cut out circles of dough and lift gently. Place cookies on prepared baking sheet. Gather up scraps of dough and reroll until too little is left to roll out.
Bake cookies until firm to the touch,20 to 30 minutes (this will vary depending on how thinly you rolled your dough). Remove and let cool. They will continue to crisp up as they cool.
Place a metal bowl over a pot of gently simmering water, not allowing the bowl to touch the water. Melt the oil and chocolate together in the bowl, stirring until smooth. Remove from heat and stir in the peppermint extract.
Dip the cookies into chocolate, using two forks to turn over and fully coat cookie. Lift out the cookie and gently tap the fork on the side of the bowl to remove excess chocolate, then place on a waxed paper lined baking sheet.
Refrigerate until fully set.
*Cook's Notes: some chocolate melts more thickly than others. Cocoa butter is the best way to thin out the coating. Butter and coconut oil are okay but some chocolate seems to end up more thick when using dairy.