Preheat oven (electric cooker: 175°C/circulating air: 150°C/gas: see manufacturer). Line a baking tray with baking paper. Chop the chocolate coating. Melt half in a hot water bath. Cream butter, sugar, vanilla sugar and 1 pinch of salt with the whisk of the mixer.
Stir in the egg. Mix flour, baking powder and cocoa, stir in. Stir in the melted chocolate coating and fold in the remaining chopped chocolate coating.
Place approx. 8 dough blobs (1 tbsp. dough each) on the baking tray at a large distance, as the dough will run apart during baking. Bake in a hot oven for 12-15 minutes. Remove and let cool on a cake rack.
From the remaining dough bake about 8 more cookies in the same way.
Stick 2 chocolate lentils as eyes with some sugar writing on the cookies, then dab the pupils on the lentils with the writing. Mix the powdered sugar and egg white with the whisk of the mixer. Pour into a piping bag with a very flat piping nozzle.
Spray the icing on the cookies like a gauze bandage, so that only the eyes look out, and let it dry for at least 2 hours.