I am new to this website. I just finished a Wilton Decorating Basics Course after sitting on the fence for a long time. The one thing that got me to do it is my son's upcoming 5th birthday next week - we are celebrating it on May 12. I have also offered to make the cake for his friend's bithday next sunday. She wants roses and flowers on her cake.
I used this recipe last year for his cake and it was yummy:
The quantities are for two 8" rounds. I recently bought an 11x15" Wilton rectangular pan. Can anybody tell me an easy way to calculate what proportions of this recipe I should use to make it that size? Will doubling the recipe be ok? I was thinking of doubling it and then filling the pan halfway. If any remains I can make it into cupcakes. But what if it is not enough for the larger pan after doubling?
Any help is appreciated.