Melt dark chocolate and butter in a double boiler.
Crack the eggs into a bowl and whisk them.
Add the melted chocolate and butter to the eggs and mix well.
Sift in almond flour, unsweetened cocoa powder, and baking powder.
Mix all ingredients evenly to make the batter.
Line a baking pan with parchment paper, pour in the batter, and spread it evenly.
Bake in a preheated oven at 170°C (338°F) for 20–25 minutes.
Let it cool completely and cut into desired sizes.