Place the Oreo cookies into a food processor and pulse until cookies turn into fine crumbs. (You can also put them in a gallon-sized ziploc bag and crush them with a rolling pin.) Add melted butter to the crumbs and stir until moistened.
Pour the cookie crumbs into a 9-inch x 13-inch baking dish and press the crumbs into the bottom to make an Oreo crust. Refrigerate while you prepare the other layers.
In a large bowl, mix the cream cheese, sugar, milk, and vanilla together until smooth. Fold in 1 tub of Cool Whip (or 3 cups of whipped cream) to make it light and fluffy. Spread the mixture over the crust into an even layer.
In a mixing bowl, whisk together pudding mix and milk. (Don’t follow package directions, use the amount of milk listed here. It sets up thicker for easy cutting). Spread the pudding evenly over the cream cheese layer, be careful not to mix them together.
Top the pudding with the other tub of Cool Whip (or whipped cream) and sprinkle regular or mini chocolate chips on top.
Refrigerate for at least 4 hours (or freeze for 1 hour if you’re in a hurry) before serving.
Make your own whipped cream by whipping 1 1/2 cups heavy cream with 3 tablespoons powdered sugar and 1 teaspoon vanilla until medium peaks form. This will yield about 3 cups of whipped cream. You'll want to double this if you're substituting whipped cream throughout this entire recipe.