Whisk together the 2 cups of milk and box of Chocolate sugar-free/fat-free pudding mix until no clumps remain. Set inside the refrigerator for the pudding to set, at least 15 minutes.
Reserve 2 tablespoons of crushed Oreos for later. Combine remaining Oreos with melted butter until well distributed. Press Oreo/butter mixture into an 8X8 pan until the bottom is covered. Crust should be tightly packed. Set pan in the freezer to set, at least 15 minutes.
Whisk together 1 1/3 cups Greek yogurt with 13g of vanilla sugar-free/fat-free pudding mix. Then, fold in 6 tablespoons of light cool whip. At this time, you can taste and see if you’d like this layer to be sweeter. If so, add in more Vanilla pudding mix 1 g at a time. It will minimally change the macros.
Remove Oreo crust from the freezer. Carefully (so the Oreo crust isn't disturbed) spread the Greek yogurt mixture over the crust evenly.
Remove pudding from the refrigerator and pour it on top of the Greek yogurt layer. Set 8X8 pan in the refrigerator, at least one hour.
After the hour, spread remaining cool whip over the pudding layer. Then, top cool whip with remaining Oreo crumbs. Set dish back in the refrigerator, at least a couple hours, to set. If possible, overnight or a day to set is preferred!