Between their ooey-gooey softness and irresistible cinnamon sugar interior, there's a reason why cinnamon rolls are a perennial favorite amongst sweet-toothed breakfast lovers. Not only are they delicious, but they're also a time-tested classic with a familiar flavor profile that people know and love. That said, if you're feeling a little daring and want to give your cinnamon roll some zing, it may be time to add a little lemon curd into the mix.