Heat oven to 325°F. Line the bottom of a 9 inch springform pan with parchment and lightly grease the sides. Wrap the outside of the pan in two snug layers of heavy duty foil.

Stir graham cracker crumbs, melted butter, sugar, and a pinch of salt. Press firmly into the bottom of the pan. Bake for 8 minutes, then cool.

Melt white chocolate in short bursts in the microwave, stirring often, until smooth. Let it cool to just warm.

Beat cream cheese and sugar on medium until smooth, about 2 minutes.

Mix in eggs one at a time.

Add vanilla, sour cream, and heavy cream. Beat just until combined and silky.

With the mixer on low, slowly pour in the melted white chocolate so it blends without seizing. Mix until even and creamy.

Spread half the batter over the crust. Dot with spoonfuls of raspberry jam and swirl gently with a knife. Top with the remaining batter.

Place the foil-wrapped pan in a roasting pan. Pour hot water around it to reach about halfway up the sides.

Bake for 60 to 70 minutes, until the edges are set and the center still wobbles slightly.

Turn off the oven, crack the door, and let it rest for 30 minutes.

Remove from the water bath, unwrap the foil, and cool fully on a rack. Chill for at least 6 hours or overnight.

Lift off the ring, warm a knife in hot water for clean slices, and garnish with fresh raspberries if desired.