Black-and-White Cookies

Sift the powdered sugar into a large bowl.

Add the flour, salt and vanilla sugar. Add the butter in small pieces and quickly knead everything into a smooth shortcrust dough.

Weigh out 500 g of dough and wrap it in cling film.

Knead the cocoa powder into the remaining dough and also wrap it in cling film.

Chill both dough portions in the refrigerator for 1–2 hours.

Roll the light and dark dough each into an equally sized rectangle.

Brush the light dough thinly with egg white, then place the dark dough on top.

Carefully roll the dough up from the long side as tightly as possible.

Chill the roll for at least 30 minutes.

Preheat the oven to 175 °C (convection).

Cut the well chilled roll into slices about 0.5 cm thick and place them on baking sheets lined with parchment paper.

Bake the cookies in batches for 10–12 minutes.

Let the cookies cool completely on a wire rack.