A few summers ago, I was puttering around my apartment, semi-listening to an online interview with a band whose name I no longer remember. I hadn't been paying close attention, but my ears perked up when the show's host asked the group what their drink of choice was. One of the musicians answered that he was currently in love with a cocktail called the Black Derby, a variation of the classic Brown Derby—a concoction of bourbon, grapefruit juice, and honey created at Los Angeles restaurant Vendome back in the midcentury heyday of Hollywood cinema. In place of honey, the Black Derby swaps in molasses, giving the drink its namesake dark twist. With a leisurely evening stretching in front of me and the ingredients at hand, I whipped one up—and found I was in love with it, too.