Sprinkles aren't something that it had occurred to us to make at home until pastry chef Monica Glass of Philadelphia's Sbraga Dining showed up in our test kitchen, toting a bowl of pastel-colored, beautifully irregular bits. "You made these?" gasped everyone who wandered by, before immediately reaching in and stealing a pinch. Turns out, it's quite easy: sprinkles are really just a variation on royal icing, a stiff frosting made from beating egg whites and sugar. Glass adds a little coloring and flavoring, pipes thin lines on a sheet pan, and lets them air dry overnight. Once dry, she breaks the lines up into colorful little sprinkly bits to serve atop ice cream or cakes.