Preheat the oven to 350°F and line a large baking sheet with parchment paper.
In a medium sized mixing bowl, combine flour, cocoa powder, baking powder and salt with a fork. Mix well and set aside.
In a separate mixing bowl, cream together the butter and sugar using an electric hand or stand mixer. Mix until smooth and fully combined.
Add egg, vanilla, and peppermint extract. Mix again until smooth.
Add flour mixture in, half at a time, and mix until fully combined and dough-like. It will be thick.
Remove dough from the bowl and place on the baking sheet with parchment paper. Using your hands, flatten the dough onto the baking sheet pressing downward.
Use a rolling pin to smooth and roll out the dough to about ¼ - ½ inch thick.
Place the baking sheet in the refrigerator to chill for 1 hour.
When chill time is complete, begin cutting your dough.
Using a 2-inch round cookie cutter, cut rounds from dough.
Line 2 baking sheets with parchment paper.
Place cookie dough rounds on the prepared baking sheets at least 2-inches apart. Do this until your baking sheet fills up.
Bake for 10 to 12 minutes.
When done, cool the cookies on the pan to room temperature.
When your cookies have completely cooled, prepare the chocolate topping.
Topping
Add the chocolate wafers to a microwave safe bowl. Microwave on 50% power for 1 minute. When done, stir well and add the vegetable oil and peppermint extract. Microwave on 50% power for 30 second intervals, stirring in between, until the chocolate is silky smooth.
Using two forks or dipping tools, dip each cookie into the melted chocolate, covering it completely before placing it back on the baking sheet.
Repeat this process, working one cookie at a time. When all cookies are covered in chocolate, place them back in the refrigerator for 30 minutes before serving.
Recipe Tips
Be sure to use dark chocolate melting wafers and not milk chocolate.Keep the cookies stored in the refrigerator.Cookie Texture: Once the cookies are at room temperature, they should be able to stand up on their own, without folding over. The cookies will be firm on the outside and soft, chewy, and moist on the inside.These cookies will remain pretty thin while cooking. You don’t want to make these very thick as thin mints are traditionally ½-inch thickThese cookies should not spread much while baking.These cookies have the perfect amount of peppermint flavor! They are truly so tasty. However, you can increase the amount. I do not recommend adding more than ½ teaspoon to the batter. Presentation Tip: if you’re serving these cookies to a crowd, garnish with mint leaves for a wow effect.