Preheat your oven to 350 degrees f, and spray a 9x13 inch pan with cooking spray. Set aside.
In a large mixing bowl, whisk together cake mix, oil, water, and eggs, per package directions.
Pour into prepared 9x13 inch pan.
Bake according to the package directions- 30-35 minutes.
Lay 9-10 Milano cookies onto a plate, set aside.
Then, heat your chocolate chips in a microwave safe bowl, on 20 second increments, stirring well in between. Add to a plastic sandwich sized storage bag, and snip the very tip off of the bag. Use the melted chocolate to write “RIP” onto your Milano cookies.
Place cookies into the refrigerator to allow chocolate to set.
Next, add chocolate cookies to a food processor, and blitz to crumbs. Set aside.
Scoop the chocolate frosting out of the container and into a microwave safe bowl.
Microwave for 20 seconds, and stir well. The frosting should be pourable.
Pour the frosting evenly over the cake.
Sprinkle oreo crumbs over the frosting.
Decorate the cake with RIP cookies, candy pumpkins and gummy worms. Enjoy!