Prepare the Crust:

1. Mix the Crust Ingredients: In a medium bowl, combine the graham cracker crumbs, sugar, and melted butter. Stir until the mixture is well combined and the crumbs are evenly coated with butter.
2. Press the Crust into the Pan: Press the mixture into the bottom of a greased 9×9-inch baking dish or a similar-sized square pan. Use the back of a spoon to firmly pack the crust. Place it in the fridge to chill while you prepare the filling.

Prepare the Filling:

3. Mix the Cream Cheese and Sugar: In a large mixing bowl, beat the softened cream cheese and granulated sugar with an electric mixer until smooth and creamy.
4. Add the Eggs: Add the eggs one at a time, beating well after each addition until fully incorporated.
5. Add the Sour Cream, Lemon Juice, Zest, and Vanilla: Stir in the sour cream, lemon juice, lemon zest, and vanilla extract until the mixture is smooth and fully combined.
6. Pour the Filling into the Crust: Pour the cheesecake filling over the prepared graham cracker crust, spreading it evenly with a spatula.

Bake the Cheesecake Squares:

7. Bake the Cheesecake: Preheat the oven to 325°F (160°C). Bake the cheesecake squares for 35-40 minutes, or until the edges are set and the center is slightly jiggly. The cheesecake should firm up as it cools.
8. Cool and Chill: Allow the cheesecake to cool to room temperature, then cover the dish and refrigerate for at least 3 hours, or until fully chilled and set.

Serve and Garnish:

9. Cut the Cheesecake into Squares: Once chilled and firm, remove the cheesecake from the fridge and slice it into squares.
10. Garnish and Serve: Optionally, top with fresh whipped cream and lemon slices or zest for a beautiful presentation. Serve chilled.