Crack the eggs and separate the whites from the yolks.
Whisk the egg whites thoroughly to make meringue.
Mix milk, protein powder, and erythritol into the yolks.
Gently fold the meringue into the yolk mixture in 2-3 parts.
Pour the batter into an oven-safe mold.
Bake in a 180°C oven for 25-30 minutes.
Let it cool and cut into bite-sized pieces.