Flüssiger means "liquid" in German, and the Flüssiger Strudel, or "Liquid Strudel" as its more often called by regular customers, is the signature drink at the Wunderbar in Grünauer, Kansas City's premier Austrian restaurant. Scott Beskow mixes the Flüssiger Strudel from freshly squeezed lemon juice, rum, egg whites and leftover strudel syrup. If you don't have fresh-baked strudel on hand, Beskow suggests substituting a simple syrup made from sugar, apple cider and cinnamon sticks. The sweet-tart combination is delicious as an apéritif or dessert drink.