Goguma mattang (고구마 맛탕), which is Candied Korean sweet potatoes, is made from deep-fried pieces of sweet potato that's candied with a golden brown, hard candy shell on the outside but fluffy soft on the inside! The hard, caramelized candy coating gives these Korean sweet potatoes a beautiful sheen and caramel color that makes this the perfect sweet potato dessert any time! Be careful not to cook the caramel too long as it can burn very quickly. If they taste too bitter, then it cooked for too long and burned.