Measure out ¼ cup Oreo cookie crumbs and set aside.
Combine remaining cookie crumbs with butter and mix together. Press crumbs into the bottom of a 9x13" pan.
In a mixing bowl, beat together cream cheese, sugar, and 2 Tablespoons of cold milk until thoroughly mixed together. Add in 1¼ cups Cool Whip and mix well.
Spread cream cheese mixture over Oreo crust in the pan. Stick in the fridge while you prepare the next layer (you could even stick it in the freezer if you want).
In another mixing bowl, mix together pudding mixes and remaining 3 cups of milk for about 2 minutes. Add in peanut butter, mix well. Spread peanut butter mixture over cream cheese mixture in the pan.
Let dessert stand for about 5 minutes to let the pudding thicken.
Spread remaining Cool Whip over the top and sprinkle with remaining Oreo cookie crumbs. Let chill in the fridge for about 4 hours or until the dessert firms up.