In a small microwave-safe bowl, add the gelatine and water. Whisk until dissolved and leave to bloom for a few minutes. Microwave for about 15 seconds, or until the gelatine melts. Set aside to cool slightly, ensuring it remains liquid when you use it.
In a separate bowl, whip the cream on high speed until firm peaks form. Place the bowl in the fridge while you prepare the rest of the filling.
In a large mixing bowl, add the cream cheese, mascarpone, and sugar. Beat with an electric mixer for 1 minute until smooth and creamy. Beat in the vanilla extract. Add the liquid gelatine and beat until fully combined.
Add about one-quarter of the whipped cream into the cream cheese mixture and gently fold through with a spatula. Then fold in the remaining cream until smooth and fluffy.
Pour the cheesecake mixture into the prepared crust, smoothing the top with a spatula.
Place in the fridge for at least 6 hours (or overnight) until firm and set.