Costco's half-sheet cakes are available in vanilla or ... Those in the know will ask the bakery to score the right-size slices of cake ahead of time for perfect portioning. Why would you buy ...

There are only two size options: A 10-inch round cake serving 16 people or a half-sheet cake serving 48 people. There are also just two flavors: A vanilla cake with vanilla cheesecake mousse ...