Roughly chop the cashews. Cream butter, sugar, vanillin sugar and salt with the whisk of the hand mixer. Stir in the egg. Also stir in nuts, flour and baking powder. Halve the dough.
Mix cocoa, espresso powder and chocolate drops into one half and use a tablespoon to place 6 piles of dough on a baking tray lined with baking paper. Press the cookies slightly flat and bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) on the upper shelf for about 12 minutes. Pull the cookies from the baking tray on paper and let them cool down. Coarsely chop the chocolate coating and mix into the light-coloured dough. Place 2 more dark piles of dough on a baking paper (dark dough should now be used up) and 4 light piles. Bake in the same way as the first baking tray and pull the paper off the tray. Remove the first cookies from the paper. Use baking paper from the other side again. Put the last 4 light piles of dough on the paper and bake.
Place 2 more dark piles of dough on a baking paper (dark dough should now be used up) and 4 light piles. Bake in the same way as the first baking tray and pull the paper off the tray. Remove the first cookies from the paper. Use baking paper from the other side again. Put the last 4 light piles of dough on the paper and bake. Let it cool down
Waiting time approx. 20 minutes