Make sure that your cakes are cooled down and ready for frosting before you start assembling.
You can make the ghosts in advance and keep.
In a mixing bowl, take the butter at room temperature and add vanilla essence. Slowly sift in the icing sugar and keep beating with an electric hand beater or a stand mixer till the sugar incorporates with the butter.
Initially it will look like you need more butter but trust me, this is more than enough butter for a lot of buttercream.
Once the buttercream is quite thick, take one third of it into a piping bag fitted with a round tip.
On a tray, fix a parchment paper with a little bit of butter cream so that it doesn't shift. Then using steady hands, pipe the ghosts onto the parchment paper.
You need to apply pressure for the first blob, then release and apply little more pressure and repeat the process three to four times to make a conical ghost. Do this to make about 20 to 24 ghosts.
Then using a forcep, stick chocolate chips as eyes for the ghosts and for the mouth if you want to (i forgot to). Place the tray in the refrigerator to harden.
Now add black food colour to rest of the butter cream and mix nicely till it has a nice shine and gloss.
Take your cakes and place the large cake on a turn table or a tray, whichever you have.
WIth a sharp bread knife, cut the round top of the cake so that it has a flat surface. Then with a palette, spread the butter thinly on top and the sides of the cake. This is called crumb coating and it seals all the crumbs of the cake.
Transfer the cake to the refrigerator and take the smaller cake. Repeat the process as the bigger cake and crumb coat it and transfer to the refrigerator.
After about fifteen minutes, take the bigger cake out and apply a generous amount of black buttercream to it. Then take the smaller cake and apply a generous amount of buttercream to that too and transfer very gently right on top of the bigger cake.
Sprinkle the chocolate sprinkles all over the cake and on the sides.
Finally take the ghosts out of the refrigerator and decorate the cake with the ghosts.
Your easy halloween ghost cake is ready.