For the potter head of your family, there is no better birthday gift than a Harry Potter poster cake. As soon as the recipient's eyes catch a glimpse of a round buttercream cake frosted with an edible Harry Potter poster with his or her name and Happy Birthday written on it, the receiver's happiness will soar on cloud nine. Avoid placing the photo and poster cake in a refrigerator as the chilled droplets can spoil the photo on the top of the cake.