Drain the cherries and collect the juice in a saucepan. Mix 4 tablespoons sugar and cinnamon.
Bring milk, 1 tablespoon sugar, vanilla sugar and 2 tablespoons butter to the boil. Add semolina while stirring and bring to the boil. Then remove from heat and let it swell covered for about 5 minutes. Separate the egg. Beat the egg white until stiff, add 1 tablespoon of sugar and a pinch of salt.
Whisk the egg yolk and cream and stir into the semolina porridge. Fold in the beaten egg white. Fill the semolina porridge into four bowls.
Bring cherry juice and 1-2 tbsp. sugar to the boil. Stir starch and 2 tablespoons cold water until smooth. Stir the starch into the boiling juice and simmer for 1 minute. Stir in cherries and rum.
Heat 75 g butter until it is lightly browned. Serve semolina porridge warm or cold with the hot rum cherries. Sprinkle with the butter, sprinkle with cinnamon sugar.