Prepare the Cookie Crust: Begin by finely crushing the chocolate sandwich cookies. You can do this by placing them in a large zip-top bag and crushing them with a rolling pin, or for a finer, more even crumb, pulse them in a food processor until they resemble fine crumbs.
Once the cookies are crushed, transfer them to a medium-sized bowl. Pour the melted butter over the cookie crumbs and mix thoroughly until all the crumbs are moistened.
Press about two-thirds of the buttered cookie crumbs evenly into the bottom of a 9×13-inch baking dish. Use the back of a spoon or your fingers to create a firm, compact layer. Set the remaining one-third of the cookie crumbs aside for later.
Make the Creamy Filling: In a large mixing bowl, combine the instant vanilla pudding mixes with 4 cups of cold whole milk. Whisk vigorously for about 2 minutes, or until the pudding begins to thicken. Set aside for 5 minutes to allow it to set further.
In a separate large bowl, using an electric mixer, beat the softened cream cheese until smooth and creamy, about 1-2 minutes.
Gradually add the powdered sugar to the cream cheese, beating until well combined and fluffy. Stir in the vanilla extract.
Gently fold the thawed whipped topping into the cream cheese mixture until no streaks remain. Be careful not to overmix, as this can deflate the whipped topping.
