Preheat the oven to 325ºF and grease a donut pan very well.

In a medium bowl, whisk together the coconut flour, sweetener, cocoa powder, protein powder, baking powder, and salt. Stir in the eggs, melted butter, and vanilla extract, then stir in the liquid until well combined.

Divide the batter among the wells of the donut pan. If you have a six-well donut pan, you may need to work in batches.

Bake for 16 to 20 minutes, until the donuts are set and firm to the touch. Remove and let cool in the pan for 10 minutes, then flip out onto a wire rack to cool completely.

In a medium shallow bowl, whisk together the powdered sweetener and cocoa powder. Add the heavy cream and vanilla and whisk to combine.

Add enough water until the glaze thins out and is of a “dippable” consistency, without being too watery.

Dip the top of each donut into the glaze. Sprinkle with any decorations and let set for about 30 minutes.