In a small pot, add the raspberries and sugar. Bring to a simmer over medium heat and cook for 2-3 minutes. Mash with a spatula.
Combine water and corn starch and stir into sauce to thicken. Set aside to cool completely (you can speed this up by pouring into a new bowl and placing in the fridge).
In a medium bowl, combine graham cracker crumbs and melted butter. Press into the bottom and 1″ up the sides of a 9-10″ pan. Set aside.
In a medium bowl, stir together white chocolate and 1/2 cup cream. Microwave on high for 40 seconds, then stir until completely smooth (heat another 15 seconds if necessary). Place in the fridge to cool.
In a large bowl, beat cream cheese with an electric mixer until smooth. Add sugar, vanilla, and remaining 1/2 cup cream and beat on high until light and fluffy.
Add melted white chocolate and beat on medium speed until incorporated.
Place fresh or thawed raspberries into the bottom of the crust and pour the cheesecake filling over top, smoothing with a spatula.
Drop teaspoonfuls of raspberry sauce on the top, and gently swirl. Save remaining sauce for serving.
Chill at least 5 hours or overnight before serving. Serve with remaining raspberry sauce and fresh raspberries as desired.