In a medium bowl, mix together the chocolate pudding mix and 1 1/2 cups of milk until smooth and well blended. Pour into the graham cracker crust.
In a clean bowl, beat cream cheese with an electric mixer until soft, then mix in confectioners' sugar. Fold in 2 cups of the whipped topping, and spread on top of the chocolate pudding layer.
Whisk together the vanilla pudding mix and 1 1/2 cups of milk until well blended. Spread over the top of the cream cheese layer. Spread the remaining whipped topping over the top. Chill for at least 30 minutes before slicing and serving.