Place the whole Oreo cookies in the bowl of a food processor and pulse them until they turn into crumbs and start to resemble dirt.
Place half of the Oreo crumbs in a 13x9-inch baking dish, flattening the layer with a spoon to make it even.
In a large mixing bowl, combine the chocolate pudding powder and whole milk. Whisk it until it's thickened then set it aside.
In a second mixing bowl, combine the cream cheese with the butter using a handheld mixer, then add the powdered sugar. Mix them until they're light and fluffy.
Add the cream cheese mixture to the chocolate pudding, mixing it on low speed until incorporated.
Fold in the Cool Whip until there are no more white streaks in the chocolate.
Using a soft silicone spatula, dollop the chocolate mixture on top of the Oreo crumbs, being careful not to move the layer of crumbs around too much.
Smooth out the top of the chocolate layer as evenly as possible, and then spoon the remaining Oreo crumbs on top.
Place the baking dish in the refrigerator to chill for 2 hours and serve.