I am fast approaching my DD haunted castle B-Day cake. What do I use for a base for the pillars. I was thinking maybe pringles cans covered in fondant or BC. Didn't know how BC will hold up on the sides of can without sliding. Help with ideas please I am starting to stress can you tell

Bump!

you could always get some gumpaste mix and mix that up with water, and then use the gumpaste on a plastic wrap lined pringles can or paper towel roll and then when it's completely hard pull the paper towel roll out and then you have a nice and hard hollow tower which you can stick beside your cake on the cake board adhering it with royal icing and hten once it's stable you can fill it with candy, toys, etc. for your DD and her friends at the party!

Oh, I love KHalstead's idea of filling the empty tubes with candy! So clever!
Debbie Brown has a castle cake in one of her books, and she uses twinkies for the towers! 3, I think. If I recall, she does a square stacked cake, iced in buttercream, then she stacks the twinkies, one tower on each corner of the cake. She sandwiches them together with buttercream, then also ices them with buttercream. The buttercream from the square cake and from the towers bonds together and holds the whole thing in place. That cake has small pieces of fondant shaped like rocks covering the whole thing, so it works, but I suppose if you were wanting to decorate it any other way it would be more difficult.
I hope that helped somewhat.
Good luck!

Thanks for your help. I haven't done anything with gumpaste yet. But will look into that. We were going to put a rock like on the pillars. The treats inside would be great if I can figure out for sure how to do the gumpaste. How long does it take to dry??