Preheat the oven to 180°C (356°F).
Add eggs and erythritol to a bowl and mix well.
Sift in almond flour, unsweetened cocoa powder, and baking powder, then mix evenly.
Melt unsalted butter in a double boiler or microwave, add it to the batter and mix.
Pour the batter into financier molds.
Bake in the oven at 180°C (356°F) for 15-20 minutes.