1. Make the Crust

1. Preheat oven to 325°F (163°C).
2. Mix graham cracker crumbs, sugar, and melted butter in a bowl until evenly combined.
3. Press the mixture firmly into the bottom of a 9-inch springform pan.
4. Bake for 10 minutes, then set aside to cool.

2. Prepare the Cheesecake Filling

1. In a large mixing bowl, beat cream cheese and sugar until smooth and creamy.
2. Add eggs one at a time, mixing on low speed until just combined.
3. Mix in sour cream, heavy cream, lemon juice, lemon zest, and vanilla extract until smooth.
4. Toss the blueberries in flour and gently fold them into the batter.

3. Assemble and Bake

1. Pour the filling over the cooled crust and smooth the top.
2. Wrap the bottom of the springform pan in foil and place it in a larger pan filled with 1 inch of hot water (water bath).
3. Bake for 55–70 minutes, or until the center is just set but still slightly jiggly.
4. Turn off the oven, crack the door, and let the cheesecake cool inside for 1 hour.
5. Remove from oven and chill for at least 6 hours or overnight.

4. Make the Blueberry Sauce

1. In a saucepan over medium heat, combine blueberries, sugar, and ⅓ cup water. Cook until berries begin to burst.
2. In a small bowl, mix cornstarch with 2 tablespoons water to make a slurry.
3. Stir the slurry and lemon juice into the berries. Simmer until thickened, then remove from heat.
4. Stir in vanilla extract. Let cool completely before spooning over cheesecake.

5. Serve

1. Once the cheesecake is fully chilled, top with the cooled blueberry sauce.
2. Slice with a clean, warm knife for best presentation.