For the compote, clean, wash and chop the rhubarb. In a saucepan, mix with approx. 125 g sugar and leave to stand for approx. 15 minutes.
Add 200 ml water and 1 sachet of vanilla sugar and bring everything to the boil. Cover and simmer for about 5 minutes. Stir starch and 5 tablespoons of water until smooth. Stir into the boiling compote and simmer while stirring for about 1 minute.
Season with sugar and let it cool down.
For the cream meringue, divide into pieces. Whip the cream until stiff, while pouring in 1 sachet of vanilla sugar. Mix mascarpone, quark and 125 g sugar. Fold cream first, then 80 g meringue into the cream.
Pour into a large bowl. Spread the compote over it. Sprinkle the rest of the meringue over it and dust with cocoa.