Beat the soft fat with half the sugar until foamy. Separate the eggs. Stir the egg yolks one after the other into the fat-sugar mass. Alternately stir in flour and milk. Beat the egg whites until stiff, slowly adding the remaining sugar. Slide the beaten egg whites onto the dough. Sprinkle with hazelnuts and fold into the dough with a whisk.
Grease glass baking tray or fat pan and sprinkle with sugar. Spread the dough smooth on top. Halve and stone the apricots. Spread on the dough with the cut surface facing upwards, sprinkle with decorating sugar and bake in a preheated oven (electric range: 175 °C/ gas: level 2) for approx. 55 minutes. Let cool on a cake rack. Cut into pieces and sprinkle with icing sugar and sugar crystals. Serve with whipped cream