Crush the chocolate sandwich cookies until fine crumbs form. Mix the cookie crumbs with the melted butter. Press this mixture firmly into the bottom of a 9×13 inch baking dish. Chill the crust for 15 minutes.
In a medium bowl, beat the softened cream cheese and powdered sugar together until smooth. Gently fold in half of the thawed whipped topping until just combined. Spread this cream cheese mixture evenly over the chilled crust.
In a separate large bowl, whisk together the instant chocolate pudding mix and the cold milk for two minutes until the mixture begins to thicken. Let it sit for five minutes, then spread the pudding mixture over the cream cheese layer.
Spread the remaining half of the whipped topping evenly over the pudding layer.
Sprinkle the mini chocolate chips over the top layer.
Cover the dish and refrigerate for at least 4 hours, or preferably overnight, before slicing and serving.
Notes
For a firmer crust, you can bake the crust at 350°F for 10 minutes, but this recipe is designed to be completely no-bake.
Use cold milk for the pudding to ensure it sets properly.
You can substitute the chocolate sandwich cookies with graham crackers mixed with cocoa powder for a slightly different base flavor.