01 - Set oven to 350°F. Line a 9-inch square baking pan with parchment paper, ensuring the edges overhang for easy removal.
02 - In a bowl, combine graham cracker crumbs, melted butter, sugar, and salt. Press the mixture firmly into the bottom of the prepared pan. Bake for 8 minutes, then cool slightly.
03 - Combine raspberries, sugar, and lemon juice in a small saucepan. Cook over medium heat, mashing berries until thickened, about 5 minutes. Strain to remove seeds and let cool.
04 - Beat cream cheese and sugar until smooth. Add eggs one at a time, mixing well after each. Stir in vanilla and sour cream, then fold in melted white chocolate until combined.
05 - Pour cheesecake filling over cooled crust and spread evenly. Spoon raspberry puree over the filling, swirling gently with a knife to create a marble effect.
06 - Bake 25 to 27 minutes until the center is set but still slightly jiggly. Avoid overbaking.
07 - Allow to cool at room temperature, then refrigerate for at least 2 hours before slicing into bars.