Beat the egg whites with the salt until stiff. Add half the sugar and continue beating until the egg whites become very stiff and glossy. Add the remainder of the sugar and briefly continue to beat. Spoon the mixture into 8 oval mounds on a baking tray lined with baking paper, form peaks with a fork.
Place the meringues in the lower half of an oven preheated to 120°C, reduce the heat to 100 °C and allow to dry out for approx. 1½ hrs. Then switch the oven off and leave the meringues to cool in the oven with the door open.
Bring the berries and vanilla sugar to the boil, then reduce the heat, cover and simmer for approx. 2 mins. until soft, leave to cool.
Carefully mix the whipped cream into the yoghurt. Serve the meringues with the berry compote and yoghurt cream.