Preheat the Oven:
Preheat your oven to 325°F (163°C).
Line a 9x9-inch baking pan with parchment paper, leaving an overhang on the sides to easily lift the cheesecake bars out of the pan.
Make the Crust:
In a medium bowl, combine the graham cracker crumbs, granulated sugar, and melted butter. Mix until well combined.
Press the mixture firmly into the bottom of the prepared baking pan to form an even layer.
Bake the crust for 8-10 minutes, then remove from the oven and let it cool while you prepare the filling.
Prepare the Raspberry Sauce:
In a small saucepan, combine the raspberries, granulated sugar, and lemon juice. Cook over medium heat, stirring frequently until the raspberries break down and the mixture begins to simmer.
Stir in the cornstarch mixture and continue to cook for another 1-2 minutes, or until the sauce thickens slightly.
Remove from heat and strain the sauce through a fine mesh strainer to remove the seeds. Set aside to cool.
Make the Cheesecake Filling:
In a large bowl, beat the cream cheese and granulated sugar together until smooth and creamy.
Add the eggs, one at a time, beating well after each addition.
Mix in the vanilla extract and sour cream until fully combined.
Add the melted white chocolate and mix until smooth and well incorporated.
Assemble the Cheesecake Bars:
Pour the cheesecake filling over the cooled crust and spread it into an even layer.
Drop spoonfuls of the raspberry sauce over the cheesecake filling. Use a toothpick or a knife to gently swirl the raspberry sauce into the filling, creating a marbled effect.
Bake:
Bake the cheesecake bars in the preheated oven for 35-40 minutes, or until the edges are set and the center is slightly jiggly.
Remove from the oven and allow the bars to cool completely in the pan on a wire rack.
Once cooled, refrigerate the bars for at least 3 hours, or overnight, to fully set.
Slice and Serve:
Lift the chilled cheesecake out of the pan using the parchment paper overhang.
Slice into bars and serve. Enjoy your Best White Chocolate Raspberry Cheesecake Bars with a cup of coffee or as a delightful dessert after dinner.