Make the Raspberry Sauce: In a saucepan, combine the raspberries, water, and 2 tablespoons of sugar. Cook over medium heat until the raspberries break down, stirring occasionally. Strain the mixture to remove seeds, then return the sauce to the saucepan. Dissolve cornstarch in a small amount of water and add to the sauce. Bring to a boil, stirring constantly until thickened. Set aside to cool.

Prepare the Crust: Preheat the oven to 325°F (163°C). Mix the crushed Oreo cookies with melted butter. Press the mixture into the bottom of a springform pan. Bake for 10 minutes, then set aside to cool.

Make the Cheesecake Filling: In a large bowl, melt the white chocolate chips in a double boiler or microwave, stirring until smooth. In another bowl, beat the cream cheese and ½ cup of sugar until smooth and creamy. Gradually add the melted white chocolate and whipping cream, mixing until combined. Beat in the eggs one at a time, then stir in the vanilla extract.

Assemble the Cheesecake: Pour half of the cheesecake filling on top of the crust in the prepared pan. Dollop about 4 tablespoons of the raspberry sauce on top of the filling. Carefully swirl the raspberry sauce into the filling using a knife or toothpick. Pour the remaining cheesecake filling over the swirled layer and smooth the top.

Bake: Place the pan in a larger baking dish and fill the dish with hot water halfway up the sides of the springform pan. Bake for 55-65 minutes, or until the center is set but still slightly jiggly. Remove the cheesecake from the water bath and let it cool to room temperature. Refrigerate for at least 4 hours or overnight.

Serve: Drizzle the remaining raspberry sauce over the chilled cheesecake before serving.