Maple syrup enhances many foods, but it's also terrific in cocktails. Whereas simple syrup is simply sweet, maple lends flavor, richness, and nostalgia. "People respond to it," says Brad Farran, head bartender at New York City's Clover Club, "because many of us grew up eating it." He uses the syrup to complement the roundness of apple brandy or to contrast aquavit's traditional caraway flavor. But the syrup's best bar partner may be rye. "Rye tends to be aged in oak, so both are woodsy," Farran notes, "but the syrup adds depth." With citrus juice, they make up what he calls a "holy trinity of flavors" in his Prospect Park Sour: spicy, rich, and with a balancing acidity. The final touch, herbaceous amaro, brings out the syrup's vegetal qualities. The result is at once approachable and complex. Farran likes a mid-season amber syrup, which he warms to room temperature so that it mixes evenly in the drinks.