Crush the chocolate sandwich cookies into fine crumbs using a rolling pin or food processor; set aside.
In a mixing bowl, whisk together the instant chocolate pudding mix with cold milk until well combined and the mixture starts to thicken, about 2 minutes.
Gently fold the whipped topping into the pudding mixture to make it creamy and fluffy.
Spread a layer of crushed cookies at the bottom of your serving dish, creating a ‘dirt’ base.
Spoon half of the pudding mixture over the cookie layer, smoothing it into an even layer.
Add gummy worms on top of the pudding layer, burying some slightly into the pudding for a hidden effect.
Repeat with remaining crushed cookies and pudding, creating additional layers and hiding more gummy worms as desired.
Finish with a final sprinkle of cookie crumbs on top to resemble fresh dirt, and insert remaining gummy worms for a spooky touch.
Cover the dish and refrigerate for at least 2 hours to allow flavors to meld and the texture to set.
Once chilled, serve the dirt cake with extra gummy worms on top if desired, and enjoy the playful, gooey texture and chocolaty flavor.