Stir red fruit jelly with cherry nectar until smooth and divide into 4 deep plates. Cut the vanilla pod lengthwise and scrape out the pulp. Mix quark with vanilla pulp, cinnamon and a few drops of sweetener.
Beat the egg white until stiff and fold loosely into the quark. Using 2 moistened tablespoons, form 8 dumplings in succession and place 2 in each case in a plate with a cold dish. Serve decorated with lemon balm.