Preheat your oven to 350 degrees.
In a small bowl, stir together the coconut milk and apple cider vinegar and set aside.
Whisk together the eggs, coconut sugar and melted coconut oil in a medium mixing bowl.
Measure out all the dry ingredients and whisk well in another bowl.
Pour half the coconut milk and half the dry ingredients into the egg mixture. Whisk until just incorporated. Add in the remaining milk and flour, followed by the vanilla. Stir gently, making sure all the flour is mixed in. The batter will be thick and wet, like cake batter.
Grease 12 donut tins very well, then spoon in the batter, taking care not to overfill.
Bake for 12 minutes, then remove the pans from the oven and set on a cooling rack. Allow the donuts to cool in the pans for about 5 minutes.
During this time, make the glaze by pouring the coconut milk, cocoa powder, powdered sugar, and vanilla into a small bowl. Stir like crazy until it forms a thick, smooth, silky glaze. Add more milk or powdered sugar as needed.
Run a butter knife around the edges of each donut to release from the pans. Place donuts on the cooling rack, then put a silpat or sheet of parchment paper underneath the cooling rack to catch any drips.
Carefully dip the donuts in the glaze. They will be pretty soft, so use a fork if needed to lift them out of the glaze bowl. Top with coarse salt. Alternatively, dust the donuts in powdered sugar and a pinch of cinnamon.
Enjoy warm with a cup of coffee or a glass of milk.