Clean, wash and cut the rhubarb into pieces. Mix with 2 tablespoons of sugar and leave to stand for 15-20 minutes. Grease the casserole dish (approx. 20 cm long) and sprinkle with semolina. Mix 2 tbsp. sugar and cinnamon.
Bring milk and 1 pinch of salt to the boil. Stir in 2-3 tablespoons of sugar, vanilla sugar and semolina. Let it swell for about 5 minutes at low heat while stirring.
Separate eggs. Stir the egg yolks into the hot semolina porridge. Beat egg whites until stiff and fold in carefully.
Put half the semolina pudding into the casserole dish. Spread rhubarb on top and sprinkle with 1-2 tbsp. sugar. Spread the remaining semolina on top. Sprinkle everything with cinnamon sugar.
Bake the rhubarb semolina casserole in a preheated oven (electric oven: 200 °C/circulating air: 175 °C/gas: level 3) for 30-40 minutes until golden brown.