Wiktionary
dirt cake
n. A kind of American dessert made from broken cookies and pudding, sometimes with gummy worms added, and resembling dirt.
Wikipedia
Dirt cake
Dirt cake is a general term for several American cake recipes that use sandwich cookies and pudding in combination with other ingredients to create desserts that have a dirty look. The simple dessert is made by combining crushed Oreo cookies on top of chocolate pudding or cream cheese, and adding gummy candy worms on top. Variations include vanilla wafers, vanilla pudding, and cream cheese pudding in the recipe.