Begin by crushing the entire package of Oreos using a food processor. Reserve one cup of the crushed Oreos to use as a topping once the lasagna is assembled.

In a small bowl, combine the remaining Oreo crumbs with melted butter, ensuring the mixture is evenly coated. Press this crumb mixture firmly into the bottom of a 9 x 13-inch baking dish to create the crust.

In a large mixing bowl, blend half of the Cool Whip, softened cream cheese, and powdered sugar using an electric mixer. Beat until smooth and creamy. Spread this mixture evenly over the Oreo crust and transfer the dish to the refrigerator to chill while preparing the next layer.

In a separate bowl, whisk together the chocolate instant pudding mix and cold milk for several minutes until it begins to thicken. Once the pudding has reached a thicker consistency, spread it evenly over the cream cheese layer. Let the pudding layer sit for about 10 minutes to allow it to firm up.

After the pudding has set, spread the remaining Cool Whip over the pudding layer, smoothing it out evenly. Sprinkle the reserved Oreo crumbs on top as a finishing touch.

Chill the Oreo Lasagna for at least 2 hours before serving to allow the layers to set properly.