Heat oven to 350°F. Lightly spray a 12 to 14-inch pizza pan with cooking spray. Set aside.

Prepare the brownie mix using the ingredients and instructions on the box. Once prepared, pour the brownie batter onto the prepared pizza pan. Use a rubber or icing spatula to spread the batter evenly across the pan.

Next, place in the preheated oven and bake for 20 - 23 minutes. Once the edges are set and crisp, remove the brownie pizza from the oven and allow them to cool completely on a cooling rack.

While the pizza is baking, crush the Oreos and Heath bars by placing them into two separate resealable bags.

Next, pound the bags with a rolling pin or a similar heavy item until they are crushed. Place them in individual bowls and set them aside.

Once completely cooled, use an icing spatula to spread chocolate icing over the top of the brownie crust. Sprinkle the crushed Oreos over the icing. Next, use orange cookie icing to create a spider web design on the chocolate icing.    

You will want to use a piping bag to put the orange frosting in the bag to make it easier to make the orange drizzle across this Halloween cookie cake.   

Let's finish by loading this pizza up with toppings! Use the sprinkles as a border. Distribute the crushed Heath bar, candy corn, edible eyes, and m&m's evenly.

Cut into equal pieces and enjoy!