Beat 3 egg whites with the whisks of the hand mixer until stiff, adding half of the powdered sugar. Pour the beaten egg whites into a large bowl. Again beat 3 egg whites until stiff, add the remaining icing sugar. Also pour into the bowl. Mix the beaten egg whites quickly with a whisk
Fold in the almonds and fill the mixture into a greased, round tart mould (28 cm Ø) with lift-off base. Bake in the preheated oven (electric oven: 150 °C/ convection oven: 125 °C/ gas: see manufacturer) on the middle shelf for 15-20 minutes
Meanwhile wash the apricots, cut them in half and remove stones. Cut the apricots into thin slices. Mix sugar, sour cream, eggs and pudding powder with the whisk of the hand mixer
Remove the bottom from the oven. Turn up the temperature of the oven (electric oven: 175 °C/ circulating air: 150 °C/ gas: see manufacturer). Carefully pour the sand casting onto the base. Carefully spread apricot slices on top as well. Bake the cake on the lower rack for about 25 minutes. Remove from the oven and leave to cool on a cake rack for about 2 hours. Carefully lift the cake out of the tin, arrange on a cake plate and dust with icing sugar
waiting time approx. 2 hours