Thaw the raspberries in a bowl. Mix the cornstarch with a little water. Bring the raspberries to the boil with the vanilla sugar and 2 tablespoons of sugar in a small saucepan until they disintegrate into a pulp and add the mixed starch, bring to the boil again briefly and set aside to cool.
Mix the yogurt, cream cheese and 6 tablespoon sugar. The mass will be very runny, but this will allow the biscuits to soak up nicely, and it will be very tasty.
Layer everything in a baking dish as follows: First butter biscuits, then yogurt cream, raspberry sauce, butter biscuits, yogurt cream, raspberry sauce, butter biscuits, etc. Finish with yogurt cream.
Place in the refrigerator for at least 4 hours, preferably overnight. Cover thickly with chocolate sprinkles before serving.