Step 1: Preheat your oven to 350°F (175°C). For the crust, combine graham cracker crumbs, 1/4 cup sugar, and melted butter in a medium bowl until well mixed. Press firmly into the bottom of a 9-inch springform pan. Bake for 8-10 minutes, then remove and let cool completely on a wire rack. Reduce oven temperature to 325°F (160°C).
Step 2: Prepare your springform pan for a water bath. Wrap the outside of the pan with two layers of heavy-duty aluminum foil, ensuring it covers the sides completely to prevent water seepage. Set aside in a large roasting pan.
Step 3: In a large mixing bowl, using an electric mixer, beat the softened cream cheese on medium speed until completely smooth and lump-free, about 2-3 minutes.
Step 4: Gradually add 1 ¾ cups granulated sugar to the cream cheese, beating on low speed until just combined and smooth, scraping down the sides of the bowl as needed.
Step 5: Add the sour cream, heavy cream, vanilla extract, lemon juice, and lemon zest (if using) to the mixture. Beat on low speed until just combined and smooth. Do not overmix.
Step 6: Add the eggs one at a time, beating on the lowest speed just until each egg is incorporated. Scrape down the bowl after each addition. Stop mixing as soon as the last egg is combined to avoid incorporating too much air.
Step 7: Carefully pour the cheesecake batter over the cooled crust in the prepared springform pan. Gently tap the pan on the counter a few times to release any large air bubbles.
Step 8: Place the roasting pan with the springform inside onto the middle rack of your preheated oven. Carefully pour hot water into the roasting pan around the springform pan, filling it with about 1 inch of water.
Step 9: Bake for 60-75 minutes, or until the edges are set but the center 2-3 inches still jiggle slightly when gently shaken. The internal temperature should be around 150°F (65°C).
Step 10: Turn off the oven, prop the oven door open slightly (about an inch) with a wooden spoon, and let the cheesecake cool in the oven for 1 hour. This slow cooling helps prevent cracks.
Step 11: Remove the cheesecake from the oven and the water bath, then carefully remove the aluminum foil. Let it cool completely on a wire rack at room temperature for another 1-2 hours.
Step 12: Once completely cool, cover the cheesecake loosely with plastic wrap or foil and refrigerate for at least 6-8 hours, or preferably overnight, to allow it to firm up and flavors to meld.
Step 13: To serve, run a thin, sharp knife around the inner edge of the springform pan before releasing the sides. Slice with a hot, clean knife (dipping in hot water and wiping dry between each slice for perfect cuts). Serve plain or with your favorite toppings.