Clean, wash and cut the rhubarb into pieces of about 1 cm. Bring 200 ml water, rhubarb, 1 packet of vanillin sugar and 75 g sugar to the boil in a pot. Cover and let simmer for 6-8 minutes at low to medium heat.
In the meantime, pick the raspberries. Stir sauce powder and 3 tablespoons of water until smooth. While stirring let it run into the boiling rhubarb compote. Bring to the boil and simmer for about 1 minute. Stir the raspberries, except for 1 tbsp for decoration, into the compote. Remove from the heat, let cool down a little.
Pour the rhubarb, except for 1-2 tbsp, into a large dessert bowl and allow to cool. Mix yoghurt, quark, 1 packet of vanillin sugar and 75 g sugar. Pour the cream onto the rhubarb. Crumble the pastry and sprinkle on the cream. Decorate with remaining raspberries and rhubarb compote.