Preheat oven to 350° F. Line a baking sheet with parchment.
Combine all cookie ingredients in a bowl. Stir to form a dough. Freeze the dough for about 5-10 minutes as it makes it much easier to roll out and cut.
Once the dough is chilled, roll it out and cut into circles with a cookie cutter or small jar lid. I found the shape of a champagne glass turned upside down was perfect.
Bake cookies for 7 minutes. As they cool they will firm up.
While you make the chocolate coating, freeze the cookies so the chocolate will stick well. For the coating, mix the coconut oil and chocolate chips in a small saucepan (or, if you prefer, a microwave-safe bowl). The coconut oil makes the chocolate much smoother and easier to coat the cookies. Heat the mixture on low or microwave for 30 seconds to one minute until oil and chocolate are melted; stir until smooth. Once melted, stir in the peppermint extract. Dip cookies in chocolate and place on a parchment-lined plate, and freeze.
I store these in the freezer once done for the classic crispiness of Thin Mints!