Preheat your oven to 325°F (160°C).
In a mixing bowl, combine graham cracker crumbs, melted butter, and sugar. Mix until well combined and crumbly.
Press the crust mixture firmly into the bottom of a 9-inch springform pan. Bake in the preheated oven for 10 minutes, then remove and let it cool.
In a separate mixing bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Gradually add sugar and vanilla extract, mixing until well blended.
Add each egg, one at a time, mixing well after each addition. Mix in the sour cream until smooth.
Pour the cheesecake filling over the cooled crust, spreading it evenly. Bake for 50-60 minutes, until the edges are set and the center is slightly jiggly.
Turn off the oven, crack the door open, and let the cheesecake cool in the oven for 1 hour to prevent cracking. After that, refrigerate for at least 4 hours, preferably overnight.
While the cheesecake is chilling, prepare the strawberry topping. In a saucepan, combine sliced strawberries, sugar, lemon juice, and cornstarch (if using). Cook over medium heat until strawberries release their juices and the mixture thickens slightly, about 5 minutes. Let it cool.
Once the cheesecake is fully set, remove it from the springform pan and pour the strawberry topping over it before serving.