I need to cover double 6 & 9" round cakes and was wondering if this recipe would be enough to cover them or should I be doubling it?

500g marshmallows, 1kg pure icing sugar & 2 TBS water

Thanks

well let me see 500g is 1.10pounds and 1kg is 2.2 pounds.....I would say you are going to need to double that if your cakes are 4' high. If you check the wilton site they have a chart you can check and from what I can tell you will need 2.40pounds of fondant. If you want it in metric that would be 38oz of fondant or 1kilo of fondant. Hope that helps.

In the Wilton guide I'm assuming that is based on 2 inch pans so what would it be for 3 inch pans?
Am I wrong in assuming if you use 2 in. pans double stacked you get the 4 in. cake & if using the 3 in. pans its a 6 in. stacked cake?

I believe you assume correctily.