PLACE cream cheese, sugar and liqueur in large bowl of electric mixer fitted with paddle attachment. Beat on medium speed until well blended. Fold in half of the whipped topping.
ARRANGE 20 cake slices on the bottom of each of 2 full (2-inch) hotel pans. (Or, for trial recipe, arrange 10 cake slices on the bottom of 1 half [2-inch] hotel pan.) Drizzle 1/2 cup of the coffee over cake slices in each pan. (Or, for trial recipe drizzle 1/4 cup of the coffee over cake slices.)
SPREAD half of the cream cheese mixture evenly over cake slices in pans; top with layer of half of the remaining cake slices. Drizzle 1/2 cup of the remaining coffee over ingredients in each pan (or use 1/4 cup of the remaining coffee for trial recipe). Cover with remaining cream cheese mixture.
REPEAT layers of cake and coffee; top with remaining whipped topping. Sprinkle with grated chocolate. Refrigerate until ready to serve.