Place about 3/4 of the Oreo cookies in a large resealable plastic bag and crush them into fine crumbs using a rolling pin, or pulse in a food processor. Set aside for layering. Roughly chop the remaining 1/4 of the cookies to use for topping.

In a large mixing bowl, use an electric mixer to cream together the softened cream cheese, softened butter, and powdered sugar until light, fluffy, and well combined, about 2-3 minutes. Scrape down the sides of the bowl as needed.

In a separate large bowl, whisk together the cold milk and instant vanilla pudding mixes until the mixture begins to thicken, about 2 minutes. Let it sit for 5 minutes to set up fully.

Gently fold the thawed whipped topping into the cream cheese mixture until no streaks remain. Then, gently fold the prepared pudding into this mixture until everything is well combined and smooth.

Spread about one-third of the crushed Oreo crumbs evenly into the bottom of a 9x13 inch baking dish or a trifle bowl. Top with half of the creamy pudding mixture, spreading it gently to the edges. Repeat with another third of the Oreo crumbs and the remaining pudding mixture. Finish with the last layer of crushed Oreo crumbs, ensuring the top is fully covered like 'dirt'.

Cover the dish tightly with plastic wrap and refrigerate for at least 2 hours, or preferably overnight, to allow the flavors to meld and the cake to set firmly.

Before serving, arrange the chopped Oreo pieces and gummy worms or candy flowers on top for a fun 'dirt' effect. Scoop and serve chilled.