Add eggs and erythritol to a bowl and mix together.
Add almond flour, baking powder, and salt, and mix well.
Add cocoa powder and unsweetened soy milk and form a batter.
Pour the batter into a donut mold.
Bake for 15 minutes in a preheated oven at 180°C (356°F).
After cooling, melt sugar-free chocolate in a double boiler and coat the top.