Mix the cookie crumbs and melted butter until combined, then press down on the bottom of an 8 inch (20 cm) springform cake pan (or line a regular cake pan with plastic wrap). Place in the refrigerator while you make the filling.
In a medium bowl beat together the cream cheese, sugar, zest and juice until creamy. Set aside.
In a large bowl beat the cold cream until stiff peaks appear, set aside
In a small pot add the milk and sprinkle the gelatine on top, let stand one minute, then place the pot on low heat and heat just until the gelatine has dissolved, stirring often (1-2 minutes), do not boil, then immediately remove from heat. Add a heaping tablespoon of the cream cheese mixture to the gelatine mixture and stir gently to combine.
Fold the gelatine into the remaining cream cheese mixture, then gently fold it into the whipped cream, mix until combined.
Remove the cookie base from the fridge, spoon the cheesecake filling evenly on top, cover with plastic wrap and refrigerate 4-5 hours or even better overnight. Before serving top with the blueberry sauce if desired.
FOR THE BLUEBERRY TOPPING
In a medium pot mix together the berries, sugar, cornstarch, water and lemon juice. Bring to a boil then lower the heat and simmer until desired thickness. Pour into a clean bowl and refrigerate 1-2 hours. It will thicken as it cools.
Notes
To dissolve the leaf gelatine, just soften the leaves in cold water for about 5-10 minutes, then squeeze the excess water. Add the leaves to the liquid you want to set. If your liquid is cold, stir it gently in a saucepan over very low heat until the gelatine dissolves, of course never let the liquid boil.If you don’t like to use gelatine then you can substitute with powdered agar in equal amounts. This recipe calls for 1 1/4 tablespoons of gelatine, so you would use 1 1/4 tablespoons of agar powder instead.If you prefer you can use the same amounts of orange, madarine orange or even lime. I just made this with orange for Christmas and I drizzled it with melted white chocolate before serving. So good!Wrap it tightly still in the pan with plastic wrap or place in an airtight container. It will keep for up to five days in the refrigerator.It's best to freeze the cake without the topping or caramel sauce, those can be added before serving. Be sure to let the cake set first, then wrap the pan tightly in plastic wrap, place it in a freezer safe bag or container before freezing.It will keep for up to three months if properly stored in the freezer. To thaw the frozen cake, place it still wrapped in the fridge and let it thaw overnight.