The best brunches always have some sort of pastry or sweet item in the spread. After all, what goes better with frittatas and breakfast potatoes than something sweet, silky and carby? And that’s why the Dutch baby, an underrated breakfast dish you can make in a cast iron pan, is the perfect thing to serve this spring. Also known as a German pancake, hootenanny, pannecocken, Bismarck or Dutch puff, the Dutch baby isn’t totally dissimilar to a Yorkshire pudding in that it’s a baked popover-type dish. However, instead of using beef fat, Dutch babies use butter and can be sweetened with sugar and vanilla. But all of that sugar and eggs can sit heavy, especially if you’re starting your day with a Dutch baby. To remedy that issue, this lightened-up recipe uses just one egg and several egg whites and omits any sugar. However, if you want to sweeten this back up, you can add …