Preheat oven to 350°F. Spray a donut pan with non-stick spray and set aside
In a large bowl, whisk together the flour, cocoa powder, baking powder, baking soda, salt, and sugar
In a separate bowl, whisk together egg, peppermint extract, instant coffee, whole milk, sour cream, and melted butter
Gently fold the wet ingredients into the dry ingredients until just combined
Pipe or spoon the batter into the prepared donut pan
Bake for 10-12 minutes, until a toothpick comes out clean
Remove from the oven and allow the donuts to cool in the pan for 5 minutes, then flip out onto a cooling rack and cool completely
Make the glaze by placing the chocolate, peppermint extract, and neutral oil into a microwave safe bowl and heat in 20-second increments, stirring in between, until melted and smooth (about 1 minute)
Dip each donut into the chocolate glaze and decorate with a sprinkle of crushed candy canes if desired. Allow to set and enjoy!
Store leftovers: baked donuts are generally best eaten the same day, however, if you have leftovers, store remaining donuts in an air-tight container in the fridge for 1-2 days