Add the cornstarch, lemon juice, and warm water to a small bowl and whisk together until dissolved.

Combine the raspberries and sugar in a medium saucepan over medium heat, stirring continuously for 3 minutes.

Add the cornstarch mixture and cook for another 3 minutes, smashing the raspberries as they cook.

Puree the raspberry mixture in a food processor and strain the puree. Set aside to cool.

Preheat oven to 325°F (163°C). Line a 9-inch springform pan with parchment paper and grease the sides.

Combine the crust ingredients in a bowl and press into the bottom and sides of the springform pan.

Bake for 10 minutes and then set aside to cool.

Wrap the outside of the pan with aluminum foil.

Reduce oven temperature to 300°F (148°C).

In a large bowl, beat the cream cheese, sugar, and flour on low speed until smooth.

Add the sour cream, lemon juice, and lemon zest and mix until combined.

Add eggs one at a time, mixing slowly after each addition, then add egg yolks.

Add two tablespoons of the cheesecake filling to the cooled raspberry filling.

Fill the crust with about ¾ of the cheesecake filling.

Drop spoonfuls of half the raspberry filling onto the cheesecake and swirl.

Add remaining raspberry filling over the top and swirl again.

Place the springform pan inside a larger pan and fill with warm water halfway up the sides.

Bake for 1 hour 25 minutes, until the center is set but jiggly.

Turn off the oven, leave the door closed for 30 minutes.

Crack the oven door for another 30 minutes to cool.

Refrigerate the cheesecake to cool completely.

Remove from the springform pan and serve on a dish.

Top with raspberries and lemon slices, refrigerate until ready.