Soak the gelatine. Mix buttermilk, lemon juice, sugar and vanillin sugar. Squeeze the gelatine, dissolve over low heat. Mix 2 tablespoons of buttermilk with the gelatine. Then stir into the remaining buttermilk. Chill for about 30 minutes until it starts to gel
Drain the peaches and cut them into thin slices, except for 2. Line 4 dessert bowls with the peach slices
Whip half the cream until stiff, fold into the buttermilk. Pour the cream into the bowls and leave to set in the fridge for at least 4 hours (or overnight)
Whip the rest of the cream until stiff and fill into a piping bag with star-shaped spout as desired. Spray one tuff each onto the cream (or use a spoon). Cut the remaining peach halves in half and cut them in a fan shape. Place on the cream and sprinkle with pistachios. Decorate with lemon balm if desired.