Step 1: Crush the entire package of Oreo cookies (including the cream filling) finely in a food processor or by hand in a Ziploc bag. Reserve about 1/2 cup of crumbs for topping. Divide the remaining crumbs evenly among 8-10 individual serving cups (8-10 oz capacity) to form the bottom layer.
Step 2: In a large mixing bowl, beat the softened butter, cream cheese, and powdered sugar with an electric mixer until light, fluffy, and thoroughly combined, about 2-3 minutes. Scrape down the sides of the bowl as needed.
Step 3: In a separate bowl, whisk together the cold milk and instant pudding mix for about 2 minutes, until thickened. Let it sit for 1-2 minutes to fully set.
Step 4: Gently fold the thawed whipped topping into the cream cheese mixture until just combined. Then, carefully fold in the prepared pudding mixture until smooth and uniform, being careful not to overmix.
Step 5: Spoon about half of the creamy pudding mixture over the cookie crumbs in the individual cups, spreading gently to create an even layer.
Step 6: Sprinkle another layer of crushed Oreo crumbs over the creamy mixture in each cup.
Step 7: Add the remaining creamy pudding mixture to the cups, filling them almost to the top. Gently spread smooth.
Step 8: Top each cup generously with the reserved crushed Oreo crumbs. Arrange 2-3 gummy worms on top of the 'dirt' in each cup, making them peek out playfully.
Step 9: Chill the Dirt Cake Dessert Cups in the refrigerator for at least 2-4 hours, or ideally overnight, to allow them to set completely and for the flavors to meld. Serve cold.