In a mixing bowl, combine graham cracker crumbs, sugar, and melted butter. Mix until well combined.
Press the mixture into the bottom of a 9-inch springform pan to form an even layer. Bake for about 10 minutes, then remove from the oven and let it cool.
Make the Cheesecake Filling:
In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth and creamy.
Gradually add the sugar and vanilla extract, mixing until well combined.
Add the eggs one at a time, mixing just until combined after each addition. If using, mix in the sour cream until smooth.
Pour the cheesecake filling over the cooled crust, smoothing the top with a spatula.
Bake the Cheesecake:
Bake in the preheated oven for about 50-60 minutes, or until the center is set and only slightly jiggly. Turn off the oven and leave the cheesecake inside for an additional hour to cool gradually, which helps prevent cracking.
Remove from the oven and let it cool completely at room temperature. Then, refrigerate for at least 4 hours or overnight for best results.
Prepare the Strawberry Topping:
In a medium bowl, combine sliced strawberries, sugar, lemon juice, and cornstarch (if using). Toss gently to coat the strawberries and let them sit for about 15-20 minutes to release their juices.
Assemble the Cheesecake:
Once the cheesecake is chilled, remove it from the springform pan. Top with the strawberry mixture, spreading it evenly over the cheesecake.
Serve:
Slice and serve the cheesecake chilled. Enjoy the creamy texture with the fresh strawberry topping!