Crush the chocolate sandwich cookies into fine crumbs using a food processor or by placing them in a zip-top bag and crushing with a rolling pin. Set aside.
In a large mixing bowl, beat the softened cream cheese and powdered sugar together until smooth and creamy.
Add the milk and instant vanilla pudding mix to the cream cheese mixture, and continue to beat until well combined and thickened.
Fold in the whipped topping gently until fully incorporated.
In your dessert cups, layer the crushed cookie crumbs and the cream cheese mixture, starting with a layer of cookie crumbs at the bottom. Repeat the layers until the cups are filled, finishing with a layer of cookie crumbs on top.
Refrigerate the dirt cake cups for at least 2 hours to set.
Before serving, garnish with gummy worms on top of the cookie crumb layer for a fun touch.