Bake the chocolate cake in a 9×13-inch pan according to the package directions. Let it cool completely.

In a bowl, beat the cream cheese, powdered sugar, and vanilla until smooth. Fold in the whipped topping, then stir in the crushed cookies.

In another bowl, mix the peanut butter with the powdered sugar until smooth. Fold in the whipped topping.

Spread the Oreo cream layer evenly over the cooled cake.

Carefully spread the peanut butter mixture over the Oreo layer.

Cover with the remaining whipped topping.

Decorate with mini chocolate sandwich cookies, crushed cookies, chocolate syrup, and peanut butter drizzle.

Refrigerate for at least 4 hours, preferably overnight, before slicing and serving.