Crush chocolate graham crackers into fine crumbs using a food processor or a zip-top bag and rolling pin.
In a mixing bowl, add crushed graham crackers and melted butter. Mix until well combined and the mixture holds together.
Press the graham cracker mixture into the bottom of a 9×13-inch baking dish. Place in the refrigerator to set while you prepare the fillings.
In a separate bowl, prepare the instant chocolate pudding mix according to package instructions, using 3 cups of cold milk. Stir until smooth and set aside.
In another bowl, beat the softened cream cheese with powdered sugar until smooth and creamy.
Fold in the thawed whipped topping until well combined and smooth.
Layer the chocolate pudding over the chilled graham cracker crust.
Spoon the cream cheese mixture evenly over the pudding layer.
Repeat the layers, starting with pudding and then cream cheese, for a total of 3 layers (pudding, cream cheese, pudding, cream cheese).
Refrigerate for at least 2 hours to allow the dessert to set and the flavors to meld.
Before serving, drizzle the top layer with chocolate syrup or fudge sauce.