Generally, when clients ask me to do a cake with a large number of servings on a few tiers, I educate them a little and let them know that the cake would not look as nice as it would if they added one or two more tiers. However, if they insist on having the same number of tiers, I might suggest a kitchen cake (sheet cake, cutting cake etc) in addition to the 2 tiers in your case. If they don’t want that either, in your case, I would go with an 8" barrel cake with a cake board in the middle and a 12" cake with standard height. The number of servings should be close enough. If you want the number of servings to be more than 100, then make both tiers barrel. Hope this helps
Ramids Confections
