Crush chocolate sandwich cookies into fine crumbs. You can do this in a food processor or by placing them in a zip-top bag and crushing with a rolling pin.

In a mixing bowl, combine the cookie crumbs and melted butter. Mix until well combined.

In a separate bowl, beat together the softened cream cheese, powdered sugar, and vanilla extract until smooth and creamy.

Layer the cookie crumb mixture into small cups or glasses, pressing down firmly to create a base.

Spoon the chocolate pudding over the cookie crumb layer.

Top with the cream cheese mixture.

Decorate with gummy worms, plastic spiders, and chocolate shavings (if using).

Refrigerate for at least 30 minutes before serving to allow the flavors to meld and the pudding to set.