What is the birthplace of Key Lime Pie?

Like everything in the Florida Keys, Key Lime Pie goes down easy. But there’s something a little harder for locals to swallow: a new cookbook says this beloved dessert doesn’t hail from Florida. Nancy Giles talks with pastry chef Stella Parks (whose book, “Bravetart,” claims that the dessert originated in New York City), and with Key West locals (who offer their own tart opinions on challenging the pie’s birthplace).