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