01 - Preheat the oven to 350°F. Line a 9-inch square baking pan with parchment paper, leaving an overhang for easy removal.
02 - Combine graham cracker crumbs, melted butter, sugar, and salt in a bowl. Press firmly and evenly into the bottom of the prepared pan. Bake for 8 minutes. Set aside to cool slightly.
03 - In a small saucepan, combine raspberries, sugar, and lemon juice. Cook over medium heat, stirring and mashing until thickened, about 5 minutes. Strain through a fine mesh sieve to remove seeds. Set aside to cool.
04 - Beat cream cheese and sugar in a large bowl until smooth and creamy. Add eggs one at a time, beating well after each addition. Stir in vanilla extract and sour cream, then fold in melted white chocolate until just combined.
05 - Pour cheesecake filling over the cooled crust and spread evenly. Drop spoonfuls of raspberry puree over the filling. Swirl gently using a knife or skewer to create a marbled effect.
06 - Bake for 25 to 27 minutes, until the center is just set but slightly jiggly. Avoid overbaking.
07 - Cool to room temperature, then refrigerate for at least 2 hours before slicing into bars.