Ok,
So I am doing a Scooby Doo Haunted Mansion Cake for a 5th Birthday next week. I am planning on doing a 2 tiered cake as there will be approximately 30 people in attendance. I plan on icing the two tiers in purple buttercream and attaching a "Haunted Mansion" on top. I am wondering if my best bet would be to use pastillage seeing as how it dries hard or another method. Pastillage is easy enough to make and I plan on making a practice batch tomorrow but if anyone has any other tried and true methods, OR has worked with pastillage in a similar fashion and has advice, I would be glad to hear it.
Thank you in advance!

Sarah