Squeeze the curd thoroughly or drain it overnight in a sieve lined with a clean kitchen towel in the refrigerator
Drain the plums. Collect the juice. Boil up the juice with cinnamon and 1 tablespoon of sugar. Stir starch and a little water until smooth, bind juice with it. Fold in the plums. Leave to cool. Remove cinnamon stick
Preheat oven (electric cooker: 200 °C/circulating air: not suitable/gas: level 3). Grease 4 ovenproof moulds (each containing approx. 200 ml) and sprinkle with sugar. Separate the eggs. Beat egg white and vanillin sugar until stiff. Cream butter and 50 g sugar. Stir in quark, semolina and egg yolk. Carefully fold in flour and beaten egg white
Pour the mixture into the moulds. Bake on the oven rack in a hot oven for 20-25 minutes. Dust the soufflé with icing sugar. Serve with cinnamon plums