CONCORD GRAPE TOPPING: Do this step when concord grapes are available.
Slip pulp of each grape out of its skin into a medium saucepan, put skins into a large bowl, and set aside.
Cook pulp over medium heat, stirring often, until soft, 8–10 minutes
Strain into bowl with skins, pressing on solids with the back of a spoon.
Discard seeds.
Stir sugar and corn starch into grapes and cook on stovetop until thick.
Freeze the results for later use.
GRAHAM CRUST: Position an oven rack in the center of the oven and preheat to 325 degrees F.
Coat a 9-inch springform pan with cooking spray.
In a bowl, mix graham crumbs, butter and sugar.
Press into the bottom of the springform pan
Bake until the crust is slightly dry in appearance and fragrant, about 5 minutes.
Place in fridge for 2 hours to harden
CHEESECAKE FILLING: Whisk together the soft cheese, icing sugar, and lime juice until smooth, then pour in the double cream and whisk again until really thick.
Pour over the cheesecake base, making sure the top is level.
Transfer to the fridge and chill for at least 3 hours.