Whip the egg yolk with the almond powder and the icing sugar to a steady foam.
Separately whip the egg white with the sugar to a soft meringue. Combine the flour
with the cacao powder and the crushed cacao nibs, fold into the egg yolk mixture,
followed by the melted butter. Fold in the meringue. Spread over a baking tray and
bake at 180°C during 8 minutes. Store in the refrigerator.