Preheat the oven to 325°F (163°C).
Prepare the crust by mixing graham cracker crumbs and melted butter.
Press the crumb mixture into the bottom of the pan and bake for 10 minutes.
In a large bowl, beat the cream cheese and sugar until smooth.
Add the eggs one at a time, beating well after each addition.
Melt the white chocolate in a heatproof bowl over simmering water.
Fold the melted white chocolate into the cream cheese mixture.
Pour half of the cheesecake mixture over the crust.
Spoon cranberry jam over the filling and swirl gently.
Add the remaining cheesecake mixture on top.
Bake for 50-60 minutes, until the edges are set but the center is slightly jiggly.
Let the cheesecake cool in the oven with the door ajar for an hour.
Chill the cheesecake in the refrigerator for at least 4 hours or overnight.
Before serving, whip the heavy cream to soft peaks and spread over the cheesecake.
Garnish with additional cranberry jam and serve.