Generously grease a 9x13 casserole dish with cooking spray and set it aside.
To make the crust, place Oreos into a high-powered blender and blend until fine crumbs.
Place crumbs in a bowl and mix with melted butter.
Spread the crumbs evenly into the prepared pan and press down to pack it firmly. Place in the freezer to chill while preparing the next layer (about 5 minutes)
In a large bowl, cream together cream cheese and powdered sugar until creamy.
Mix in 8 oz of whipped topping until combined.
Spread mixture evenly over chilled Oreo crust and chill until set.
To make the pudding layer, add the pudding mix into a large bowl.
Gradually mix in the milk until the pudding is thick and creamy.
Spread the pudding layer onto the chilled cream cheese layer and let chill for about 5-10 minutes.
Once chilled, spread on the remaining whipped topping (8 oz) and sprinkle on the mini chocolate chips.
Refrigerate until thoroughly set (about 2 hours) and ready to serve.