A recipe may specify a jelly roll pan or a baking sheet, so what’s the difference? And do you need both? A jelly roll pan (typically 10½ by 15½ inches) is simply a smaller version of a rimmed baking sheet (about 12 by 18 inches). When it comes to equipping your kitchen, baking sheets are more versatile. You can use one to roast a large batch of vegetables, bake a dozen or more cookies, or even make a large sheet cake. A jelly roll pan is a nice-to-have addition. It’s ideal for a bûche de Noël and handy for toasting nuts or cooking asparagus. And chances are, it will fit in your dishwasher.