Mix flour, baking powder, sugar, vanilla sugar, espresso powder and 1 pinch of salt in a mixing bowl. Add bitter almond flavour, butter in flakes, eggs and 6 tablespoons of water. Knead everything first with the dough hooks of the hand mixer and then briefly with your hands to a smooth dough.
Knead the cashew nuts briefly into the dough.
Cut the dough in thirds. Form each third into a roll (approx. 28 cm long) and cover and chill for approx. 2 hours.
Line a baking tray with baking paper. Place the dough rolls on the baking tray with some distance between them and press them a little flatter. Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for about 20 minutes.
Let it cool down.
Cut rolls into slices of about 1 cm thick and place them on two baking trays lined with baking paper. Continue baking one after the other at the same temperature for about 10 minutes. Let it cool down.