Preheat Oven: Set your oven to 325°F (165°C) and grease a 9-inch springform pan.
Prepare the Crust: In a medium bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Press the mixture firmly into the bottom of the prepared pan.
Make the Filling: In a large bowl, beat the softened cream cheese and granulated sugar until smooth. Add sour cream, then eggs one at a time, mixing well after each addition. Stir in vanilla extract and melted white chocolate until fully combined.
Assemble the Cheesecake: Pour the cheesecake batter over the crust, spreading it evenly. Drop spoonfuls of raspberry preserves onto the batter. Use a knife to gently swirl the preserves into the batter, creating a marbled effect.
Bake: Place the cheesecake in the preheated oven and bake for 50-60 minutes, or until the center is set. Turn off the oven and leave the cheesecake inside with the door slightly open for 1 hour to cool gradually.
Cool and Chill: Remove the cheesecake from the oven and allow it to cool completely at room temperature. Refrigerate for at least 4 hours or overnight before serving.