Make the Blueberry Sauce:
In a saucepan, combine the blueberries, water, sugar, lemon juice, cornstarch, and vanilla. Bring to a boil, then reduce the heat and let it simmer until the mixture thickens and the blueberries soften (about 8–10 minutes). Remove from heat and let it cool completely.
Prepare the Crust:
Crush the graham crackers or tea biscuits until fine. Mix with melted butter until well combined. Press the mixture firmly into the bottom of a springform pan or deep dish to form an even crust. Place in the fridge while you prepare the filling.
Make the Filling:
In a large bowl, beat the softened cream cheese with powdered sugar, lemon juice, and vanilla until smooth and creamy.
Whip the Cream:
In a separate bowl, whip the cream until stiff peaks form. Then gently fold it into the cream cheese mixture until fully combined and fluffy.
Assemble the Cheesecake:
Spread half of the cheesecake filling over the crust. If you’d like a fruity layer inside, spoon some of the cooled blueberry sauce over this layer. Then add the remaining filling on top and smooth it out evenly.
Chill:
Cover and refrigerate for at least 6 hours or preferably overnight to allow the cheesecake to fully set.
Serve:
Once set, top the cheesecake with the rest of the blueberry sauce. Slice, serve, and enjoy!