I need to make a shoe box cake to feed 45. WHat size sheet do you suggest I start with?

I have used a 9x13 and cut it one half and stacked it...I don't think it will 45 though so you may have to go bigger with a 11x15

I usually assume a two layer 9X13 will feed 40-45.[/u]

Yes..a 2 layer full sheet 9x13 will feed 45 will but a single layer won't and I always use single layers cut and stacked for shoe boxes as the shoebox proportions are more realistic.You can make a giant shoebox with 2-9x13 stacked...

You could do a platform cake with a shoe box cake on top? This way you will have plenty of cake.