Add eggs and erythritol to a bowl and mix well.
Sift in cocoa powder, almond flour, and baking powder, then combine thoroughly.
Melt unsalted butter using a double boiler or microwave, add to the batter, and mix well.
Pour the batter into the madeleine pan.
Bake in a preheated oven at 170°C for 12–15 minutes.