Pour the margarine, flour and sugar in a bowl and mix it with an electrical mixer until you have crumbles.
Pour half of the crumbles in a bowl and the other half in another bowl.
Pour the vanilla sugar in one of the bowls, and the cacao powder in the other.
Mix first the bowl with the vanilla sugar. Mix the ingredients in to a dough.
Mix the ingredients in the bowl with the cacao powder the same way.
Now you have two dough. Divide the two dough in two, so you have two with cacao, and two with vanilla sugar.
Firm the four pieces in to evenly big rolls.
Place the vanilla sugar rolls over a cacao rolls, and press them together as a big roll. Make sure you have the white and dark side on opposite side of each other. Make a square or a round roll.
Place the roll in the fridge for ten minutes.
Preheat the oven at 200 degrees Celsius.
Take out the roll from the fridge and cut the dough roll in slices approx half a centimeter wide.
Place a baking paper on a baking sheet, and place the cookies on the baking paper.
Place the cookies in the middle of the oven for ten minutes.
Take out the cookies and let them cool down.