Use an electric mixer to beat the cream, mascarpone, powdered sugar, and vanilla in a large bowl until firm peaks form.
Spread a small amount of the cream mixture over the base of a 6-cup (1.5L) glass trifle bowl.
Dip half the hot cross bun halves briefly into the orange juice, then layer over the cream mixture.
Top with half the raspberries, then half the remaining cream mixture.
Repeat the layers with remaining hot cross buns, raspberries, and cream mixture.
Cover and refrigerate for 2 hours or until chilled.
Top with white chocolate curls or grated white chocolate before serving.