Preheat your oven to 325°F (165°C). Grease a 9-inch springform pan and line the bottom with parchment paper for easy removal.

In a large mixing bowl, beat the softened cream cheese with a hand mixer or stand mixer on medium speed until smooth and creamy (about 1–2 minutes). Add the granulated sugar and salt, and mix until fully incorporated. Beat in the eggs, one at a time, mixing on low speed after each addition. Avoid overmixing to prevent air bubbles. Stir in the all-purpose flour, sour cream, lemon extract, and lemon zest (if using). Mix until just combined and smooth.

If making a layered cake, bake your cake layer according to its recipe and let it cool completely. Place the cooled cake layer at the bottom of the springform pan. Pour the cheesecake batter over the cake layer (or directly into the pan if skipping the cake layer). Smooth the top with a spatula.

Place the springform pan on a baking sheet to catch any leaks. Bake in the preheated oven for 50–60 minutes, or until the edges are set but the center is slightly jiggly. Turn off the oven, crack the door slightly, and let the cheesecake cool in the oven for 1 hour.

Remove the cheesecake from the oven and let it cool completely at room temperature. Cover the pan with plastic wrap and refrigerate for at least 4–6 hours, or overnight, to set.

Once chilled, release the cheesecake from the springform pan and transfer it to a serving plate. Top with whipped cream, fresh berries, or a lemon glaze for an extra touch of elegance. Slice and enjoy the creamy, zesty goodness!