Prepare the cookies: Place flours, cocoa, salt, baking soda, and sugar in a food processor and pulse several times until combined. Pulse in melted oil, egg, and peppermint until mixture forms a ball of dough (dough will be slightly sticky) Wrap dough in plastic wrap and place in freezer for 20 minutes.

Once dough is chilled, remove from freezer and place on a floured surface. Roll dough out to 1/4-in thickness and use a 3-in biscuit cutter to cut out cookie rounds. Place cookies on a parchment paper-lined baking sheet.

Bake cookies at 350F 9-10 minutes or until edges just start to brown. Cool cookies 5 minutes on baking sheet, then transfer to a wire cooling rack to cool completely.

Prepare the coating: Place chocolate chips and coconut oil in a small saucepan and slowly melt over medium-low heat until smooth. Remove from heat and stir in peppermint extract. One at a time, dip cooled cookies in melted chocolate and coat both sides. Place cookies on wax paper and freeze cookies 15-20 minutes or until chocolate coating is set. Store cookies in freezer until ready to eat.