For the curd cheese soufflé, first pass the curd cheese through a sieve. Whisk the egg with the sugar, stir into the curd together with half of the melted butter, the semolina, the vanilla sugar and salt. Rinse the raisins and add them little by little.
Butter an ovenproof gratin dish, sprinkle with breadcrumbs and pour in the curd mixture. Smooth out and spread with the sour cream.
Melt the remaining butter and drizzle over the top. Bake the curd casserole in the oven heated to 170 degrees on the middle shelf for 25-30 minutes.