To accomplish this, she made a separate "show" cake, which served as a center piece but was actually just a tower of styrofoam and icing, into which she cleverly hid a large slice of real cake for the bride and groom to cut. Waiting in the back room, already cut into serving pieces, were the actual, edible sheet cakes. (I had never heard of this before...am I the last one?)
She made three sheet cakes, each a different flavor: chocolate, white raspberry, and a pina colada/pineapple/tropical combination, since the newlyweds are honeymooning in Hawaii. Truth be told, that last one sounded absolutely terrible to me, but as always, my sister convinced me otherwise, and once I tasted it I knew she was right. Job well done!