Preheat the oven to 170°C (340°F).
Melt the dark chocolate and butter together in a double boiler.
Mix eggs and erythritol in a bowl.
Add the melted chocolate and butter to the egg mixture and stir to combine.
Add almond flour, baking powder, and salt, and mix until well combined.
Shape the dough into balls and place them on a baking tray.
Bake at 170°C (340°F) for 10-12 minutes.
Let them cool to finish.