Mix the sugar, vanilla sugar, salt, egg and butter very well. Dissolve coffee powder in milk and add. Sift the flour into a bowl, add the baking powder and cocoa powder. Add the flour mixture and knead very well.
Shape the dough into rolls with a diameter of approx. 3 cm and chill for at least 30 minutes.
Preheat the oven to 180 °.
Cut slices approx. 3 mm thick from the rolls and place on a baking sheet lined with baking paper. Bake for about 10 minutes, leave the biscuits to cool on a wire rack.
Tip:
You can coat the biscuits with chocolate couverture. A frosting made from powdered sugar and orange juice also tastes very good, which gives a very fruity contrast to the coffee taste.