Crush Oreos (I like to use a food processor because it’s easy but crushing them in a ziplock baggie works too)
Add tape to the bottom of your 8 in cake board and stick to your cake turntable. Then add tape to the bottom of your 6 in cake board and stick to the center of the 8 in cake board.
Place a small dollop of frosting in the center of the 6 in cake board and place your first cake layer on top.
Add a nice layer of orange buttercream, then and your second cake layer, then add another layer of buttercream, and add your third cake layer.
Spread a thin layer of orange buttercream all over the cake as your crumb coat. Don’t worry too much about making it super smooth because it will all be covered with the final coat. Once the crumb coat is on refrigerate for 10-15 minutes.
While cake is chilling, decorate your ghosts and pumpkins. Use the writing tip to make details like eyes and mouths, and lines on the pumpkins.
Once chilled, add a thick layer of black buttercream all around the center of the cake. Press in the sprinkles and then add the ghosts and pumpkins to the black frosting. I found that halving the ghosts and pumpkins so they were thinner worked well. Chill for another 10 minutes in the refrigerator.
Add the final orange coat by frosting a large area above and below the black frosting. I found using a piping bag with the end cut off (to make a large circle) worked well to evenly frost these areas. Add frosting to the top of the cake as well.
Using the bench scraper smooth out the sides, being careful to not mix the orange into the black, but to keep a nice ledge- or fault line.
Use the offset spatula to clean up the top edge (see my notes on cake decorating here).
Make several mounds of Oreos on top of the cake, and place KitKats around the bottom of the cake (I halved each KitKat) and then refrigerate for 10 minutes.
Slide a tooth pick into the bottom of the ghosts and pumpkins, then place on top of the cake. Gently press in the headstones.
Using the green frosting and the grass tip, pipe on grass around the headstones, and around the KitKats at the base of the cake.
Enjoy!