1. Make compote: Combine all ingredients in a heavy saucepan. Bring to boil, stirring until sugar dissolves. Reduce heat and simmer until cranberries pop, 5 minutes. Let cool. (Can be prepared one day ahead; cover and refrigerate.)
2. Make pudding: Bring 1 1/2 cups milk, sugar and cocoa to simmer over medium-low heat. Remove from heat. In a bowl, whisk remaining 1/2 cup milk with cornstarch, egg yolks, vanilla and salt.
3. Slowly add hot milk to egg mixture, whisking constantly. Return to pan. Whisk over medium-high heat until pudding boils. Lower heat and whisk until pudding becomes very thick, about 3 minutes.
4. Remove from heat, add chocolate chips and stir until melted. Pour into bowl, cover surface with plastic wrap and chill for 4 hours or overnight.
5. Set aside 3/4 cup of compote. Whip cream until stiff peaks form, reserving 1 1/2 cups. Fold remaining cream gently into chocolate pudding.
6. Cover bottom of trifle bowl with ladyfingers. Add 1/3 of orange juice or liqueur. Spread 1/3 of compote over ladyfingers; cover with 1/3 of pudding mixture. Repeat, layering twice more.
7. Spread reserved cream on top. Spoon reserved compote into center of bowl. Garnish with zest and grated chocolate. Chill 1 hour; serve.