Cranberry Trifle With White Chocolate Cherries

Place juice and 1/2 cup water in a bowl. Place 1/3 cup boiling water in a heatproof bowl. Sprinkle gelatin over water and whisk with a fork until dissolved.
Stir gelatin mixture into juice mixture. Pour juice mixture into a 12-cup serving bowl or trifle bowl. Refrigerate for 3 hrs, until set.
Meanwhile, make custard: Heat half and half and milk in a medium heavy-based saucepan on low. Bring to a simmer and remove from heat.
Whisk egg yolks, sugar, cornstarch and vanilla in a large heatproof bowl until pale and creamy. Gradually whisk in the hot milk mixture until combined.
Strain into a clean heavy-based saucepan over low heat. Cook, stirring, for 8-10 mins, until custard coats back of spoon. Remove from heat and transfer to a heatproof bowl. Cover surface with parchment paper and chill for 2 hrs, until thick and cold.
To make the trifle: Arrange 16 lady finger halves on the cranberry gelatin, cut-side down, around edge of bowl. Coarsely chop remaining ladyfingers and place in center. Pour custard over chopped cookies. Smooth surface and refrigerate for 1 hr.
Line a baking sheet with parchment paper. Dip cherries into melted chocolate. Place upright on prepared tray. Leave for 15 mins, until set.
Using an electric mixer, beat cream and powdered sugar in a large bowl until soft peaks form. Spoon whipped cream over custard in serving bowl. To serve, top with cherries and dust with powdered sugar, if desired.