Ah, Key West. A land of sunshine and palm trees and Hemingway. But most importantly, Key limes. Key limes supposedly have a sweeter flavor than Persian limes, but it depends on the individual lime. Either way, Persian limes will probably work just fine in this recipe! Although Key Lime Pie is the traditional vehicle for Key limes, these Key Lime Bars are a much better option for parties and are an equally delicious way to get your citrus.