Preheat oven to 350°F (175°C). Wrap the bottom and sides of a 9-inch springform pan tightly with heavy-duty aluminum foil to prevent water bath leakage.

In a food processor, pulse graham crackers until fine crumbs form. Alternatively, crush in a zip-top bag with a rolling pin.

In a medium bowl, combine graham cracker crumbs, ¼ cup granulated sugar, and melted butter. Mix until evenly moistened.

Press the mixture firmly into the bottom of the prepared springform pan. You can use the bottom of a glass for an even layer.

Bake for 10 minutes. Remove from oven and let cool slightly while preparing the filling. Reduce oven temperature to 325°F (160°C).

In a small saucepan, combine quartered strawberries, ½ cup granulated sugar, and 2 tablespoons lemon juice. Cook over medium heat, stirring occasionally, until strawberries soften and release their juices, about 5-7 minutes.

In a small separate bowl, whisk together cornstarch and cold water to create a slurry.

Pour the cornstarch slurry into the simmering strawberry mixture, stirring constantly. Cook for another 1-2 minutes until the sauce thickens.

Remove from heat. Mash some of the strawberries lightly with a fork or potato masher if you prefer a smoother sauce with fewer large chunks. Let cool completely. Set aside about half for topping later, and the other half for swirling.

In a very large mixing bowl, using an electric mixer on medium-low speed, beat the softened cream cheese until smooth and creamy, about 2-3 minutes. Scrape down the sides of the bowl.

Gradually add 1 ½ cups granulated sugar and the all-purpose flour, continuing to beat on low speed until just combined. Do not overmix.

Beat in the vanilla extract and lemon zest (if using).

Add the eggs, one at a time, mixing on low speed after each addition until just incorporated. Do not overbeat, as this can incorporate too much air and lead to cracks.

Gently fold in the sour cream with a rubber spatula until just combined. The batter should be smooth and lump-free.

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

Dollop small spoonfuls of the cooled strawberry swirl mixture (the half you set aside for swirling) onto the top of the cheesecake batter. Use a butter knife or skewer to gently swirl the strawberry mixture through the batter, creating a marble effect.

Place the foil-wrapped springform pan into a larger roasting pan. Carefully pour hot water into the roasting pan, ensuring it comes about halfway up the sides of the springform pan. This is your water bath.

Carefully transfer the roasting pan with the cheesecake to the preheated 325°F (160°C) oven.

Bake for 60-75 minutes, or until the edges are set and lightly golden, but the center 2-3 inches still jiggles slightly when gently shaken.

Turn off the oven, crack the door open slightly, and let the cheesecake cool in the water bath inside the oven for 1 hour. This slow cooling helps prevent cracks.

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

Once completely cooled, cover the cheesecake loosely with plastic wrap and refrigerate for at least 4 hours, or preferably overnight, before serving.

Before serving, run a thin knife around the edge of the pan to loosen the cheesecake. Carefully remove the sides of the springform pan.

Top with the remaining cooled strawberry sauce and fresh strawberries for garnish. Slice and serve.