I'm using my own photo here to showcase just how easy this sprinkle cake is . . . and I'm no Betty Crocker. Whether you use an old family recipe or the trusty store-bought box, just make a round cake (single- or double-layer works), and frost it. Then cut a good-sized number (however old the birthday kid is turning) out of paper, place it on top of the frosted cake, and pour on the sprinkles (liberally!). When you peel away the paper, your number will be outlined in frosting. Touch-ups may be necessary, but it doesn't get much easier than this!
Photo: Lisa Horten