Prepare the Crust: Preheat the oven to 350°F (175°C). Line the bottom of a 9-inch springform pan with parchment paper. Lay 4 sheets of foil on a flat surface in a cross pattern. Place the pan in the center and wrap the foil tightly around the bottom and sides of the pan, ensuring no gaps or tears. Set aside.In a medium bowl, combine the graham cracker crumbs, sugar, and melted butter. Mix until the crumbs are well coated with butter. Press the mixture evenly into the bottom of the prepared springform pan and about three-quarters of the way up the sides. Bake the crust for 8 minutes, until lightly golden. Remove from the oven and let cool. Increase the oven temperature to 400°F (200°C).

Prepare the Cheesecake Filling: In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth and free of lumps. Scrape down the sides of the bowl and beat again for another minute. Add the sugar and cornstarch and continue beating on medium speed until light and fluffy (about 2 minutes). Scrape down the sides as needed.Add the eggs and egg yolk one at a time, mixing on low speed until fully incorporated. Then, add the sour cream, heavy cream, and vanilla extract. Stir gently with a spatula until combined, ensuring not to over-mix.

Bake the Cheesecake: Bring 6 cups of water to a boil for the water bath. Place the springform pan (with the baked crust) into a larger roasting pan. Pour the cheesecake filling into the crust. Carefully place the roasting pan in the oven, then pour the boiling water into the outer pan until it reaches halfway up the side of the springform pan.Bake for 10 minutes at 400°F, then reduce the oven temperature to 230°F (110°C). Bake for an additional 1 hour, making sure not to open the oven door during this time. After 1 hour, turn off the oven and crack the door open slightly, allowing the cheesecake to cool inside for another hour.

Cool and Chill: After the cheesecake has cooled in the oven for 1 hour, remove it and let it cool completely on the countertop. Once cooled, refrigerate the cheesecake for at least 8 hours or overnight.

Make the Strawberry Topping: While the cheesecake is chilling, prepare the strawberry topping. In a medium saucepan, combine half of the chopped strawberries with the sugar, cornstarch, and lemon juice. Cook over medium heat, stirring frequently, until the mixture thickens (about 5–7 minutes). Remove from heat and stir in the remaining strawberries. Let the topping cool to room temperature, then refrigerate until ready to use.

Serve: Once the cheesecake has chilled and set, carefully remove it from the springform pan and place it on a serving plate. Spoon the strawberry topping over the cheesecake. Slice, serve, and enjoy!