Now, I know it’s not technically frosting, but who doesn’t love the idea of a frosted birthday cake—even for a cat? For this, use mashed potato (it’s soft, cat-safe, and just looks so cute). You can spread it on top with a spoon or, for a bit of flair, use a piping bag. If you don’t have a piping bag, no worries—just grab a plastic sandwich bag, cut the tip off, and squeeze it on! You’ll get cute little swirls or a smooth top, depending on your mood.