Combine the graham cracker crumbs, melted butter, sugar, and salt until evenly moistened.
Press the mixture firmly into the bottom of a 9-inch springform pan. Refrigerate while preparing the filling.
Melt the chopped white chocolate in short intervals, stirring between each interval until smooth. Allow it to cool slightly.
Combine the orange juice, orange zest, sugar, and optional champagne or sparkling wine.
Beat the softened cream cheese and powdered sugar until smooth. Mix in the vanilla and citrus mixture.
Slowly add the cooled white chocolate and mix just until combined.
In a separate bowl, whip the cold heavy cream until medium-stiff peaks form.
Gently fold the whipped cream into the white chocolate cream cheese mixture in several additions.
Spread the filling evenly over the chilled crust and smooth the top.
Cover and refrigerate for at least 6 hours, preferably overnight.
Remove the cheesecake from the springform pan and decorate with whipped cream, orange zest, orange slices, or white chocolate curls.
Slice with a warm, dry knife and serve chilled.
