1. Preparing the Raspberry Filling:

To start, you’ll need to make the raspberry filling, which will give your cheesecake that gorgeous swirl. In a small bowl, whisk together the cornstarch, lemon juice, and warm water until the cornstarch is fully dissolved. Set this mixture aside.

Next, combine the raspberries and sugar in a medium saucepan and place the pan over medium heat. Stir continuously for about 3 minutes, allowing the raspberries to release their juices. Add the cornstarch mixture to the pan and continue to cook for an additional 3 minutes, using a spoon or spatula to smash the raspberries as they cook. The mixture should begin to bubble and thicken slightly.

Once the raspberry mixture is thickened, transfer it to a food processor and puree until smooth. After that, strain the puree through a fine mesh sieve to remove the seeds, leaving behind a silky smooth raspberry sauce. Set the puree aside to cool while you prepare the crust.

2. Preparing the Crust:

Preheat your oven to 325°F (163°C). To prepare the crust, line the bottom of a 9-inch springform pan with parchment paper and grease the sides. This ensures the cheesecake doesn’t stick to the pan as it bakes.

In a small bowl, combine the graham cracker crumbs, melted butter, and sugar. Stir everything together until the crumbs are evenly coated in butter. Then, press the mixture firmly into the bottom and up the sides of the springform pan to form the crust. Bake the crust for 10 minutes, then remove it from the oven and set it aside to cool. Once the crust has cooled, cover the outsides of the springform pan with aluminum foil to prevent water from seeping in during the water bath. Set the prepared pan aside while you make the cheesecake filling.

3. Preparing the Lemon Cheesecake Filling:

Reduce the oven temperature to 300°F (148°C). In a large mixing bowl, beat the cream cheese, sugar, and flour on low speed until the mixture is smooth and fully combined. Be sure to mix on low speed to avoid introducing too much air into the batter, which can cause cracks in the cheesecake as it bakes. Scrape down the sides of the bowl to ensure everything is thoroughly incorporated.

Next, add the sour cream, lemon juice, and lemon zest to the bowl, mixing on low speed until smooth and well combined. Add the eggs one at a time, mixing slowly after each addition to prevent overmixing. Finally, add the egg yolks and mix until fully incorporated. Scrape the sides of the bowl as needed to ensure the batter is smooth and lump-free.

4. Assembling the Cheesecake:

Now it’s time to assemble the cheesecake. Take two tablespoons of the cheesecake filling and stir it into the cooled raspberry filling to combine. This will help the raspberry mixture blend seamlessly into the cheesecake batter.

Pour about three-quarters of the cheesecake filling into the cooled graham cracker crust. Then, drop spoonfuls of half of the raspberry filling over the cheesecake batter. Use a knife or spatula to swirl the raspberry filling into the cheesecake batter. Drop spoonfuls of the remaining raspberry filling on top of the swirl and gently spread it evenly. Finally, use a knife or spatula to swirl the remaining raspberry filling into the cheesecake, creating a beautiful marbled effect.

Place the springform pan inside a larger roasting pan and fill the outer pan with enough warm water to come about halfway up the sides of the springform pan. The water should not touch the cheesecake batter or go above the top edge of the aluminum foil.

5. Baking and Cooling:

Bake the cheesecake for 1 hour and 25 minutes. The edges should be set, but the center should still be a little jiggly. This is normal, as the cheesecake will continue to cook as it cools. Once the cheesecake has finished baking, turn off the oven and leave the door closed for 30 minutes. This helps the cheesecake cool gradually and prevents cracks from forming.

After 30 minutes, crack the oven door slightly and let the cheesecake continue to cool for an additional 30 minutes. This process ensures that the cheesecake cools slowly and evenly, which is crucial to prevent cracks. After the cheesecake has cooled for about an hour, remove it from the oven and the water bath. Let it cool to room temperature, then transfer it to the refrigerator to chill completely. Ideally, let the cheesecake refrigerate for at least 4 hours or overnight to ensure it sets properly.

6. Serving and Garnishing:

Once the cheesecake is fully chilled and set, carefully remove it from the springform pan and place it on a serving dish. For a decorative touch, top the cheesecake with fresh raspberries and lemon slices. These garnishes not only enhance the flavor but also add a pop of color that makes the cheesecake even more appealing.

Before serving, refrigerate the cheesecake until you are ready to serve. The cheesecake is best enjoyed within 3-4 days, although it will keep for up to a week in the refrigerator.