Preheat your oven to 350°F (175°C). In a mixing bowl, combine graham cracker crumbs, granulated sugar, and melted unsalted butter until it resembles wet sand. Press this into a 9-inch springform pan and bake for 10 minutes. Let it cool completely.

In a mixing bowl, beat together cream cheese, granulated sugar, sour cream, vanilla extract, and salt until smooth. Gradually add eggs, mixing until just incorporated. Pour the filling over the cooled crust.

Place the filled springform pan inside a larger roasting pan and fill it with hot water halfway up the sides. Bake at 300°F (150°C) for 1 hour. After baking, turn off the oven and leave the cheesecake inside for an additional hour.

Remove the cheesecake from the water bath and let it cool on a wire rack for 1.5 hours. Cover and refrigerate for at least 4 hours or preferably overnight.

In a saucepan, combine diced strawberries with cornstarch and additional sugar. Cook over medium heat, stirring until thickened, about 5-7 minutes. Remove from heat, stir in chopped fresh strawberries, and let cool before spreading over the cheesecake.

Run a knife along the edges of the springform pan to remove the sides. Slice into portions and serve chilled, optionally adding extra strawberry topping or whipped cream.