Preheat the oven and prepare the pans. Preheat the oven to 350˚F. Coat 2 (7-inch) round cake pans generously with butter, then flour, tapping out any excess flour. Set aside. 

Mix the cake ingredients. Mix flour, cocoa powder, and baking powder. Sift the mixture into a large bowl. Add sugar, eggs, butter, oil, and milk. Using a hand mixer, beat the batter for about 3-4 minutes until well incorporated. Divide evenly and pour the batter into prepared pans.

Bake the cakes and cool overnight. Bake for about 50 minutes until the toothpick comes out clean. Remove from the oven, and let it cool before taking it out of the pans. Wrap with plastic wrap and place the cakes into the fridge overnight.

Make the Spiral Hill topper. To make the Spiral Hill topper we will use sugar paste. Roll it out into a 4-inch circle. Using a knife, cut the edges to make a beautiful neat circle. Press popsicle sticks into the back of the circle, and leave the circle to dry a little bit at room temperature overnight. Do not cover it. The next day, make a Spiral Hill drawing with Jack and Sally silhouettes, using a very thin paintbrush and black gel food coloring. Leave it to dry.

Make the Buttercream. To make the buttercream, add egg whites and sugar to a heat-proof bowl. Place the bowl over a pan with simmering water. Water should not touch the bowl. Constantly stirring with a whisk, heat the mixture until sugar dissolves and the internal temperature of the mixture is 160ºF. Remove the bowl from the pan and set it aside.

Add room temperature butter to a separate bowl. Beat for 5 minutes until it comes light and fluffy and becomes whiter. Set aside.

Clean the whisks very well before starting to beat the egg white with sugar. Beat egg/sugar mixture for about 15-18 minutes, using a hand mixer until stiff glossy peaks form (with a stand mixer, the process will be quicker).

Start adding butter by 1 tbsp, beating after each addition until well incorporated. After adding all the butter, beat for 1-2 minutes at a high speed. 1 ½ cups granulated sugar. You will get glossy, smooth buttercream.

Color the buttercream. Divide the buttercream into 2 equal parts. Color the one half with orange food coloring. Take a couple of tablespoons of orange-colored frosting and place it into a separate small bowl, we will need it to make the pumpkins. Take 2 tbsp of buttercream from the other half of buttercream, and color it with green food coloring (we will use it to make pumpkin stems). The remaining buttercream will be colored with purple coloring (or you can coat the cake with white buttercream and then make a thin layer of purple coloring). Leave a tiny amount of white buttercream to write RIP on cookies.

Cut layers of cake. Cut the domes from the cakes and cut the cakes into 2 equal parts to get 4 layers of cake. Make the crumbs from the cut parts (we will use them for the decoration later).

Assemble the cake. To assemble the cake, place a small amount of buttercream on a cake turntable to secure the first cake on top of it. Spread a layer of orange-colored buttercream over it. Cover with the second cake and repeat the process. Do it again with the next layers. Top with the fourth layer cake.

Make the graveyard cookies. To make the graveyard cookies, we will need any graveyard-shaped cookies, for example, Milano cookies or any others. Cut the cookies in a half and press a toothpick or small skewer into the back. Melt the chocolate. Using a fork, dip each cookie into chocolate, and place it on parchment paper to set. If you want to make some small “dirty” dots on the cookies, you can add 1 tsp of vegetable oil to melted chocolate and mix, leaving some stains. Write “RIP” on each cookie using a white buttercream.

Make the buttercream pumpkins. Using a piping bag, fitted with a tip (Decorating Round Tip 7/16″), make the pumpkins. Make the foundation and then, moving from the bottom to the top, make the shape of the pumpkin. Using a piping bag (with Decorating Open Star Tip 3/16″), with green buttercream, make the stems. Place pumpkins in the fridge for about an hour before decorating the cake.

Coat the cake with purple buttercream. Using an offset spatula, make the pattern on the sides of the cake. I covered the top of the cake with white buttercream, as we will decorate the top with cake crumbles and other elements of decoration.

Decorate the cake. Decorate with Spiral Hill topper, buttercream pumpkins, and graveyard cookies. Place into a fridge. Take it out from the fridge for about 1 hour before serving