Melt the dark chocolate and butter together in a double boiler.
In a bowl, combine the eggs and erythritol and whisk together.
Gradually add the melted chocolate and butter mixture to the egg mixture, mixing as you go.
Sift in the almond flour and cocoa powder, then gently fold together.
Spoon the batter into muffin tins in a tree shape.
Bake in a preheated oven at 180°C for 20 minutes.