Stir the gelatine into the boiling water until the crystals have dissolved.
Puree the boysenberries in a food processor. Pass through a medium to fine mesh sieve to remove seeds. Stir in the gelatine and set aside.
Whip the cream until it just starts to peak and set aside. Separately whip the egg whites adding 1 tablespoon of sugar at a time until stiff peaks form.
Whisk together the Tatua Mascarpone and pureed berries. Fold in the whipped cream and then fold in the egg whites until combined.
Spoon into 6 serving glasses and chill for 2 hours. Serve topped with extra Tatua Mascarpone and berries. Serves 6.