Mix the quark with the buttermilk and sugar, then stir in the salt, lemon juice, butter and semolina. Beat in the egg yolks. Beat the egg whites until stiff, fold evenly into the quark mixture and place in a buttered casserole dish.
At will, e.g., small apple pieces or cherries are added. Bake in a preheated oven at 200 ° C for about 30 minutes until the mixture is firm.
Sprinkled with a little cinnamon and sugar, the casserole tastes particularly good.