Arrange 12 ladyfingers in an 11x7-in. dish. Spread with half of the Nutella., In a large bowl, whisk cream and pudding mix 2 minutes. Stir in whipped topping. Spread half the mixture over the Nutella. Top with remaining ladyfingers; spread with remaining Nutella and then remaining pudding mixture. Sprinkle with grated or shaved chocolate. Refrigerate, covered, 8 hours or overnight. Refrigerate leftovers.