In a large bowl, whisk together the chocolate pudding mix and cold milk until smooth.
Let the pudding sit for 5 minutes to thicken.
Fold in the whipped topping gently until fully combined.
Add the vanilla extract and mix well.
Stir in the crushed Oreos, reserving some for garnish.
Layer the Oreo fluff mixture into serving dishes or a large trifle bowl.
Repeat the layers until all ingredients are used, finishing with the fluff on top.
Sprinkle the reserved crushed Oreos on top for garnish.
Chill in the refrigerator for at least 2 hours before serving.
Serve chilled and enjoy this delicious dessert!