If you’re looking for a finer texture and extra lightness in your cookies, consider replacing superfine sugar with granulated. The smaller crystals of superfine sugar, also known as caster sugar, trap more air when the sugar and butter are beaten together during creaming, explains Rose Levy Beranbaum in “The Cookie Bible.” The finer sugar also means the dough is less likely to crack while baking. For cookies rolled in sugar before baking, superfine provides a delicate, even coating. If you can’t find it on the shelves or don’t want to buy it, just run the granulated sugar through the food processor until it’s more finely ground (if you go too far you’ll end up with something more like icing sugar). And if you’re replacing superfine with granular, make sure you’re doing it by weight, not volume.