01 - Preheat oven to 325°F. Grease a 9-inch springform pan and line the base with parchment paper.
02 - Combine graham cracker crumbs, melted butter, sugar, and salt in a bowl. Press mixture firmly into the bottom of the prepared pan. Bake for 10 minutes, then cool while preparing the filling.
03 - Combine raspberries, sugar, and lemon juice in a small saucepan. Cook over medium heat, stirring constantly, until raspberries break down and mixture thickens, approximately 5 to 7 minutes. Push through a fine sieve to remove seeds and set aside to cool.
04 - Beat cream cheese and sugar in a large bowl until smooth and creamy. Add eggs one at a time, mixing thoroughly after each addition. Add sour cream, heavy cream, vanilla, lemon juice, and flour, then beat until just combined.
05 - Pour half the cheesecake filling over the crust. Drizzle half the raspberry sauce over the filling and gently swirl with a skewer or knife. Add remaining filling and repeat with remaining raspberry sauce, swirling again to create marbled effect.
06 - Place springform pan in a large roasting pan. Fill roasting pan with hot water to reach halfway up the sides of the springform pan.
07 - Bake for 50 to 60 minutes, until edges are set but center retains a slight wobble. Turn off oven, crack door open, and let cheesecake cool gradually for 1 hour inside the oven.
08 - Remove from oven and water bath. Refrigerate at least 4 hours or overnight before unmolding. Serve chilled with additional fresh raspberries or whipped cream if desired.