Soak gelatin. Warm the juice of an orange slightly (do not let it boil!) And dissolve the squeezed gelatine in it. Mix together the yogurt, sugar, vanilla sugar, egg yolk and all the juice. Squeeze out the gelatine and dissolve it, mix into the yoghurt mixture. Put in a cool place.
Beat egg whites and cream until stiff. When the cream begins to run streets, fold in the egg white and cream with the whisk.
Pour into one or more bowls and let set in the refrigerator.