1. Prepare the Oven and Pan:

   • Preheat the oven to 350°F (175°C).

   • Lightly grease a 9-inch springform pan and wrap the outside bottom tightly with an 18-inch square of aluminum foil to prevent water from seeping in during the water bath.

2. Make the Crust:

   • In a medium bowl, mix 1 ¼ cups graham cracker crumbs and 2 tbsp packed brown sugar.

   • Stir in 1 tbsp melted butter until thoroughly blended.

   • Press the mixture evenly into the bottom of the prepared springform pan.

   • Bake for 8 minutes until golden brown, then remove and cool on a wire rack.

3. Make the Filling:

   • In a large bowl, beat 4 (8-oz) packages softened cream cheese with an electric mixer until creamy, about 2 minutes.

   • Gradually add 1 cup white sugar, beating until fully blended.

   • Beat in 4 large egg yolks one at a time, scraping the bowl after each addition to ensure smoothness.

   • Mix in ½ cup sour cream, ¼ cup fresh lemon juice, 1 tbsp finely grated lemon zest, and 1 tsp vanilla extract until well blended.

4. Whip the Egg Whites:

   • In a separate clean bowl, beat 4 large egg whites with an electric mixer until soft peaks form.

   • Gradually add ⅓ cup white sugar in a slow stream, beating until stiff peaks form (peaks should stand upright without collapsing). Avoid overbeating to prevent graininess.

   • Gently fold ⅓ of the meringue into the cream cheese mixture using a spatula, mixing carefully to avoid deflating.

   • Repeat twice with the remaining meringue, folding until no streaks remain.

5. Bake the Cheesecake:

   • Pour the filling into the cooled crust in the springform pan.

   • Place the springform pan in a large baking pan and pour hot (not boiling) water into the baking pan to reach 1 inch up the sides of the springform pan (water bath).

   • Bake for 50–55 minutes until the top is almost set (slight jiggle in the center).

   • Turn off the oven, prop the door open about 2 inches, and let the cheesecake rest in the oven for 1 hour until fully set.

   • Remove from the oven and water bath, cool to room temperature (about 1 hour), then refrigerate for at least 4 hours, preferably overnight.

6. Make the Blueberry Topping:

   • In a small saucepan, combine 1 cup blueberries and ⅓ cup white sugar.

   • Cook over medium heat, stirring occasionally, until berries begin to break down, about 6–8 minutes.

   • Strain the mixture through a sieve or cheesecloth over a bowl, reserving the juice and discarding the pulp.

   • Let the juice cool to room temperature.

   • In a medium bowl, mix the remaining 2 cups blueberries with 1 tsp fresh lemon juice and the cooled blueberry juice.

7. Serve:

   • Just before serving, remove the cheesecake from the springform pan and place on a serving platter.

   • Pour the blueberry topping over the cheesecake, spreading evenly.

   • Slice into 12 wedges and serve chilled, optionally with extra blueberries or whipped cream.

Cooking Tips

• Softened Cream Cheese: Soften cream cheese at room temperature for 1 hour or microwave in 15-second bursts to ensure a smooth filling.

• Folding Egg Whites: Use a gentle, figure-eight motion to fold meringue into the filling to maintain airiness; avoid stirring to prevent deflating.

• Water Bath: Wrap the springform pan tightly with foil to prevent leaks; use hot tap water for the bath to avoid splashing.

• Check Doneness: The cheesecake should have a slight jiggle in the center; overbaking can cause cracks or a dense texture.

• Chilling: Refrigerate overnight for the best texture and flavor; cover loosely to avoid condensation on the surface.