Step 1: Prepare the Crust

1. Preheat the Oven: Start by preheating your oven to 350°F (175°C). This ensures that your crust bakes evenly.
2. Combine the Ingredients: In a medium-sized mixing bowl, combine the graham cracker crumbs, granulated sugar, and melted butter. Stir until all the crumbs are well-coated and the mixture resembles wet sand.
3. Press into the Pan: Using a 9-inch springform pan, press the crumb mixture firmly into the bottom and slightly up the sides. This forms a sturdy base that will hold up to the creamy filling.
4. Bake the Crust: Bake for about 15 minutes, until golden and fragrant. Remove from the oven and set aside to cool while you prepare the filling.

Step 2: Make the Creamy Lemon Filling

1. Beat the Cream Cheese Mixture: Using an electric mixer on medium speed, beat the softened cream cheese, sugar, and cornstarch together until smooth and creamy. It’s important to mix these ingredients well to ensure a lump-free filling.
2. Incorporate the Eggs: Add the eggs one at a time, mixing thoroughly after each addition. This helps to create a smooth texture and prevents the filling from becoming too dense.
3. Add Sour Cream, Lemon Juice, and Flavorings: Finally, add the sour cream, lemon juice, vanilla extract, lemon extract, and lemon zest. Mix until everything is fully combined, and the filling has a smooth, creamy consistency.
4. Pour the Filling: Pour the filling over the prepared crust, smoothing the top with a spatula.

Step 3: Bake the Cheesecake

1. Initial Bake: Place the cheesecake in the oven and bake at 350°F for 15 minutes.
2. Reduce Oven Temperature: After 15 minutes, lower the oven temperature to 200°F (93°C). Continue baking for 2 hours to 2 hours and 10 minutes, until the center of the cheesecake is set and no longer looks wet.
3. Cool Gradually: Remove the cheesecake from the oven. Run a thin knife around the edges to release it from the pan, then place it back in the oven, turn off the oven, and leave the cheesecake to cool gradually for an additional 2 hours. This step helps prevent cracking.

Step 4: Chill and Serve

1. Refrigerate Overnight: Transfer the cheesecake to the refrigerator and let it chill overnight. This step allows the flavors to meld and the texture to set perfectly.
2. Add Optional Toppings: Before serving, spread a generous layer of lemon curd on top of the cheesecake and pipe or dollop whipped cream around the edges.
3. Slice and Enjoy: Use a sharp knife to slice your cheesecake, wiping the knife between each cut for clean slices. Serve and enjoy the zesty, creamy flavors!