Preheat your oven to 350°F (175°C). Wrap the outside bottom and sides of a 9-inch springform pan tightly with several layers of heavy-duty aluminum foil to prevent water from seeping in during the water bath.

In a medium bowl, combine the graham cracker crumbs, 1/4 cup granulated sugar, and melted butter. Mix until well combined and the mixture resembles wet sand.

Press the crumb mixture evenly into the bottom of the prepared springform pan. Bake for 10 minutes, then remove from oven and let cool slightly while you prepare the filling.

Reduce oven temperature to 325°F (160°C).

In the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer), beat the room temperature cream cheese on medium speed until smooth and creamy, about 2-3 minutes. Scrape down the sides of the bowl.

Gradually add the 1 1/2 cups granulated sugar and cornstarch, beating on low speed until just combined. Be careful not to overmix, as this can incorporate too much air, leading to cracks.

Add the vanilla extract and lemon zest, mixing until just incorporated.

Add the eggs one at a time, mixing on low speed after each addition until just combined. Do not overmix; stop as soon as the yolk disappears. Overmixing eggs can also cause cracks.

Gently fold in the sour cream and heavy cream until fully incorporated and the batter is smooth. Do not use an electric mixer for this step.

Pour the cheesecake filling over the cooled crust in the springform pan.

Place the foil-wrapped springform pan into a larger roasting pan. Carefully pour hot water into the roasting pan until it reaches about halfway up the sides of the springform pan (this is the water bath).

Carefully transfer the roasting pan with the cheesecake to the preheated oven. Bake for 60-70 minutes, or until the edges are set and lightly golden, but the center still has a slight jiggle (about a 2-inch circle in the middle).

Once baked, turn off the oven and prop the oven door open with a wooden spoon. Let the cheesecake cool in the oven for 1 hour. This slow cooling prevents cracking.

Carefully remove the cheesecake from the water bath and the roasting pan. Remove the aluminum foil. Let it cool completely on a wire rack at room temperature for another 1-2 hours.

Once completely cool, cover the cheesecake loosely with plastic wrap and refrigerate for at least 6-8 hours, or preferably overnight, before serving. Chilling is crucial for the cheesecake to firm up and develop its full flavor and texture.

Before serving, run a thin knife around the edge of the pan before releasing the springform ring. Serve plain or with your favorite toppings like fresh berries or fruit compote.