In a large mixing bowl, using a hand mixer or KitchenAid mixer, beat together the cream cheese and powdered sugar until completely blended. Stir in ½ cup coarsely chopped Oreos. Fold in 1 ½ cups whipped topping.
In another mixing bowl, beat together the pudding mix and milk for 5 minutes or until the pudding has thickened.
Check the package label to see how long the pudding needs to set. Most instant pudding mixes take 5 minutes.
In a 9x13 casserole dish, place a layer of Oreo cookies.
Spoon the cream cheese mixture in dollops over the cookies and press into an even layer.
Spread the pudding over the cream cheese layer. Top with a layer of the remaining whipped topping.
Place the remaining cookies in a zip top bag and crush. Sprinkle over the whipped topping layer.
Cover and return the dish to the refrigerator to store overnight to allow the cookies to soften.
Drizzle chocolate over the crushed cookies before serving.