Preheat oven to 350 degrees. Lightly grease 2 6-slot doughnut pans with oil or butter.
In a bowl, beat the butter and sugar until combined. Whip in the eggs, one at a time, then the vanilla extract and Greek yogurt. Add the flour, cocoa powder, baking powder, and baking soda. With the mixer running, stream in the buttermilk, stirring until just combined. Do not overmix you rat bastards.
Transfer the batter into a piping bag, or a ziptop bag with a corner snipped off. Pipe the batter into the prepared doughnut pans, filling 2/3 of the way.
Bake the doughnuts for 10-12 minutes until the centers are set and an inserted toothpick emerges with just a few moist crumbs. Let cool 5 minutes in the pan, then run a knife around the edge of each doughnut and move them to a wire rack. Cool completely.
In a microwave safe bowl, heat the chocolate and coconut oil for 1 minute. Stir until the bowl is no longer warm. If needed, heat an additional 20-30 seconds until completely smooth. Stir in the peppermint extract. Cool for 5 minutes.
Place a piece of parchment paper beneath the wire rack. Dunk one side of each doughnut into the chocolate, letting excess drip back into the bowl. Place dry-side down onto the wire rack. Sprinkle with crushed peppermint bark. Let set for 8-10 minutes, or dig right in and enjoy the messiness!