Soak gelatine in cold water. Heat grape juice, 1 tablespoon sugar and lemon peel. Remove from heat. Wash the grapes, cut them in half and possibly remove the seeds. Remove lemon peel from the juice. Squeeze the gelatine and dissolve in the juice. Mix in the grapes. Pour everything into glasses. In the refrigerator, if necessary put at an angle, let it set
For the vanilla foam, pour milk into a mixing bowl. Add the sauce powder and vanilla sugar and immediately fold it in vigorously for 1 minute to prevent lumps from forming
Whip the cream until very stiff, carefully fold into the vanilla sauce. Spread the vanilla foam on the jelly. Decorate with mint leaves if necessary