01 - Preheat oven to 325°F and line a 9x9-inch baking pan with parchment paper, leaving an overhang for easy removal.
02 - Combine graham cracker crumbs, sugar, and melted butter in a bowl, then press firmly into the bottom of the baking pan. Bake for 10 minutes and let cool slightly.
03 - In a small saucepan, mix raspberries, sugar, and lemon juice. Cook over medium heat, stirring and mashing until thickened, about 5 minutes. Strain through a fine mesh sieve and cool.
04 - Beat cream cheese and sugar until smooth. Add eggs one at a time, mixing well after each. Stir in vanilla extract and sour cream, then fold in melted white chocolate gently.
05 - Pour the cheesecake filling over the crust. Add dollops of raspberry puree on top and use a toothpick or skewer to swirl the mixture gently.
06 - Bake for 30 to 35 minutes until the center is just set and edges are slightly puffed. Avoid overbaking.
07 - Allow to cool at room temperature, then refrigerate for at least 3 hours before cutting into bars.