Preheat oven to 325°F (163°C). Grease the bottom and sides of a 9-inch (23 cm) springform pan lightly with butter or nonstick spray. Cut a circle of parchment paper to fit the bottom and place it in the pan.

Combine the graham cracker crumbs, granulated sugar, and salt in a medium bowl. Pour in the melted butter and stir until all dry crumbs are moistened and mixture clumps when pressed.

Press the crumb mixture evenly into the bottom (and about 1/2 inch up the sides if desired) of the prepared springform pan using the back of a measuring cup or the bottom of a flat glass to compact. Refrigerate while preparing filling to help it set (about 10 minutes).

Optional blind-bake: bake crust for 8 minutes until fragrant and set. Remove from oven and let cool slightly. If you prefer an unbaked crust, skip the oven step and keep refrigerated.

Filling

Reduce oven temperature to 300°F (150°C) if you pre-baked the crust; otherwise preheat to 300°F (150°C) now.

In a large mixing bowl or the bowl of a stand mixer fitted with the paddle attachment, beat the room-temperature cream cheese on medium-low speed until smooth and free of lumps, about 2–3 minutes. Scrape down the sides of the bowl as needed.

With the mixer on low, add the granulated sugar and continue beating until well combined and creamy, about 1–2 minutes. Avoid overbeating; keep speed low to minimize air incorporation.

Add the sour cream, vanilla extract, lemon zest (if using), flour, and salt. Mix on low just until combined and smooth.

Add the eggs one at a time, mixing on low speed and just until each is incorporated. Stop mixing as soon as the batter is smooth — overmixing introduces air that can cause cracks.

Pour the filling over the prepared crust and smooth the top with a spatula. Tap the pan gently on the counter to release any large air bubbles. For best results, run a thin knife around the edge between the filling and the pan to help prevent cracking.

Prepare a water bath (bain-marie): wrap the outside of the springform pan tightly with two layers of heavy-duty aluminum foil to prevent leaks. Place the wrapped pan in a large roasting pan. Carefully pour hot (not boiling) water into the roasting pan until it reaches about halfway up the sides of the springform pan.

Bake at 300°F (150°C) for 55–70 minutes, until the edges are set but the center still slightly jiggles when the pan is gently shaken. Total time will vary by oven and pan. Avoid overbaking.

Turn off the oven and crack the oven door open. Let the cheesecake cool inside the oven for 1 hour to reduce temperature shock and minimize cracks.

Remove the cheesecake from the water bath, unwrap foil, and run a thin knife around the edge to loosen from the pan. Let cool to room temperature on a wire rack for 1–2 hours.

Refrigerate the cheesecake, still in the pan, for at least 6 hours or preferably overnight (8–12 hours) to fully set and develop flavor.

Topping (optional)

If using the sour cream topping: stir together the sour cream, powdered sugar, and vanilla extract until smooth. Spread evenly over the chilled cheesecake. Return to refrigerator for 15–30 minutes to set the topping.

When ready to serve, remove the sides of the springform pan. Top with fresh berries or warmed fruit compote, slice with a sharp knife dipped in hot water and wiped dry between cuts for clean slices.