Preheat the oven to 180°C (356°F).
Melt dark chocolate and butter together in a double boiler.
Add erythritol and eggs to the melted chocolate and mix well.
Add almond flour and baking powder, then knead into a batter.
Pour the batter into a pan and bake in the oven for 20-25 minutes.
Let it cool completely and cut into bite-sized pieces.