Preheat the oven to 180°C (356°F).
In a bowl, mix the eggs and Greek yogurt well.
Add protein powder, cocoa powder, almond flour, and erythritol; mix until even.
Add baking powder and salt; mix to form a smooth batter.
Pour the batter into a parchment-lined pan and spread it evenly.
Bake in the preheated oven for 20 minutes.
Let cool, then cut into desired sizes.