With a hue like a sunset captured in a glass, this aperitif is all but destined for sipping while day fades into night. Adding to its cocktail-hour allure, it's only a hair more complicated to make than a gin and tonic. After adding a splash each of zippy limoncello and bittersweet Luxardo Aperitivo to the classic combination, swirl it all together with a swizzle stick (or a spoon) and plop in a grapefruit twist — that's it! The result: a drink that's only complex in taste. Keep reading for the intoxicating recipe.