Mix the room temperature butter with both types of sugar, two eggs, vanilla sugar, salt and flour with baking powder. Mix it into a smooth dough, then add baking chocolate cut into small pieces.
Divide the mixture into 18 equal parts, form them into balls and place them on two baking trays lined with baking paper (be careful to leave enough room between the balls).
Use your hand to slightly flatten each ball and bake them for 15 minutes at 150 °C.
Even though they look pale and soft, take them out of the oven so they will not be too hard when they cool down.
