For the semolina cake, separate the eggs. Melt butter, cool and then mix with yogurt, egg yolks, sugar, vanilla sugar until creamy, about 5 minutes.
Stir in semolina, raisins and baking powder. Fold in the stiffly beaten egg whites. Line a square baking pan with baking paper and pour in the batter.
Bake the cake in a preheated oven on the middle shelf at 175 degrees for about 100 minutes. After baking, immediately pour the orange juice over the cake and let it cool in the pan.
Sprinkle with sugar and cut into cubes.