In a bowl mix together half of the flour, sugar, margarine, and all the cacao powder. Make sure to get a smooth dough with a solid brown color.
In another bowl mix together half the sugar, margarine, flour, and all the vanilla sugar.
Place both the doughs in the fridge for 30 minutes.
Take out the doughs and divide in two. Roll each part to long rolls.
Preheat the oven at 200 degrees Celsius.
Place one white and one black roll next to each other and place the opposite color on top of the rolls. Press together and shape a big squarish roll.
Place a baking paper on a baking sheet.
Cut the roll in thin slices and place on the baking sheet.
Place the cookies in the middle of the oven for 8-10 minutes.
Take the cookies out and let them cool down.