This recipes makes 3 cups of each flavor of frosting, if that ends up being more than you need to Neapolitan 1 box of brownies, you can save the leftovers for dipping other store-bought baked goods like crispy rice treats or doughnuts. The idea is to make the Neapolitan Icing flavors, then dip to your heart's content.Tip: If you refrigerate your brownies once they’ve cooled slightly, cutting clean edges is a breeze.These icings will start to stiffen as they sit. They will be good for 1/2 hour after you mix them up. If you want to make them in advance and use them later, place them in a bowl and lay a damp paper towel directly on the surface. And then cover the bowl with plastic wrap and leave at room temperature. If necessary, whisk in an additional 1-2 Tbsp. hot water to recapture proper consistency.