Preheat the oven to 200°C top/bottom heat. Line two baking trays with baking paper.
Knead the flour, butter, sugar, cocoa powder and one of the eggs into a smooth dough. Shape into a ball, wrap in cling film and leave to rest in the fridge for 20 minutes.
Divide the dough into 6 equal pieces. Roll each piece into a sausage shape with your hands.
Place three dough rolls on a baking tray and flatten them with your hands so that the dough is about 1 cm thick. It doesn't matter if it looks a little uneven.
Beat the second egg. Brush the dough pieces with it and sprinkle with coarse sugar.
Bake the trays one after the other for approx. 14 minutes. Caution: Check regularly, as the dough can quickly develop black edges.
Remove from the oven and cut into diagonal slices while the baked dough is still hot. It will harden as it cools.
