Heat oven to 325° F and grease the donut pan.
Set a sieve over a large bowl and add the flour, cocoa powder, baking soda, and salt (I always sift when using cocoa powder).
Sift, then fold together for even distribution.
In a smaller bowl, whisk the coconut milk, sugar, egg, coconut oil, and vanilla until smooth.
Add the wet ingredients to the flour mixture and mix with a whisk or wooden spoon until everything is blended. The batter will be thick.
Spoon batter into a piping bag (or into a large resealable plastic bag with the corner cut off) and pipe into the greased doughnut pan, making sure to not overfill.
Bake for 13 minutes, until a tester comes out clean.
Cool the doughnuts in the pan for 3 minutes, and then carefully turn the doughnuts onto a rack to finish cooling.
Once the donuts are completely cooled, make a glaze. This recipe originally called for a confectioners sugar type, I made a chocolate one.
Place a rack over a piece of parchment to catch any drips.
Dip the cooled donuts into the glaze and allow excess to drip back into the bowl.