Put the eggs and sugar in a bowl and mix with a whisk.
Sift in the almond flour, cocoa powder, and baking powder, then mix well.
Melt the Greek yogurt and dark chocolate together using a double boiler, then add to the batter and mix.
Divide the batter evenly into muffin cups.
Bake in a preheated oven at 170°C (340°F) for 20 minutes.