Also called a Marianito, the vermouth cocktail Vermut Preparado is found in Spain’s Basque Country (particularly Bilbao and San Sebastian), and considering the many different approaches to making the drink, the details listed here are less a formal recipe than a helpful suggestion. Feel free to adjust the proportions to your taste, and to swap other fruit liqueurs or bitter ingredients (such as an amaro or a few dashes of Angostura bitters) for those listed here. For best results, use a Spanish rojo vermouth, such as those from Timbal or Lustau, which are typically softer and less bitter than Italian rosso vermouths.