In a large bowl, whisk the flour, cocoa powder, baking powder, and salt together. Set aside.
In a smaller bowl, combine the sugar with the melted coconut oil. Add to the dry mix and stir until fully combined.
Flip dough out onto a piece of parchment paper and use your hands to push together into a round disc. Place another piece of parchment paper on top of dough and roll to about ½ inch thickness. Chill for 1 hour.
Remove from the refrigerator and let dough sit at room temperature for 20-30 minutes, to soften slightly. Preheat oven to 350°F and line a baking sheet with parchment paper.
Use a round cookie cutter to cut out cookies. Gather and re-roll scraps of dough as necessary. Arrange on prepared baking sheet and bake 12-14 minutes. Cool completely.
To make the mint chocolate coating, add peppermint extract to melted chocolate and mix well to combine. Use two forks to dip each cookie completely into the melted chocolate and place on parchment paper. Repeat with each cookie, then refrigerate for about 20 minutes to allow the chocolate to set completely.