1. Make the crust:

1. In a bowl, mix the graham cracker crumbs, melted butter, and sugar until well combined.
2. Press the mixture firmly into the bottom of a 9-inch (23cm) springform pan or pie dish.
3. Place the crust in the refrigerator to chill while preparing the filling.

2. Prepare the filling:

1. In a large mixing bowl, beat the softened cream cheese and sugar together until smooth and creamy.
2. Add the vanilla extract and lemon juice, and mix until well combined.
3. In a separate bowl, whip the cold heavy cream until stiff peaks form.
4. Gently fold the whipped cream into the cream cheese mixture until smooth and fully incorporated.
5. Pour the filling over the chilled crust and smooth the top with a spatula.
6. Refrigerate for at least 4-6 hours, or until the cheesecake is firm (overnight is best).

3. Make the blueberry topping:

1. In a small saucepan, combine the blueberries, sugar, cornstarch, water, and lemon juice.
2. Cook over medium heat, stirring constantly, until the mixture thickens and the blueberries break down (about 5-7 minutes).
3. Remove from heat and let the topping cool completely.

4. Assemble the cheesecake:

1. Once the cheesecake is set, spread the cooled blueberry topping evenly over the top.
2. Return the cheesecake to the refrigerator for 30 minutes to let the topping set.