"Jasper Soffer, bartender at the Mulberry Project in New York City, created this simple-to-prepare seasonal cocktail for our story Spring Cocktails Perfect for Brunch. The rhubarb simple syrup, Soffer explains, is simultaneously sweet and tart, not unlike a rhubarb-apple crumble or a strawberry-rhubarb pie. If you want to make this drink outside rhubarb's short early-spring season, frozen fruit makes a great substitute...."