The following is a guest blog post by Rebecca Sharpless, author of Grain and Fire: A History of Baking in the American South, available now wherever books are sold. Come Thanksgiving, pecan pie, a gooey concoction of syrup, eggs, and butter, and pecans, will be on many American tables. Along with pumpkin and apple, it's one of the most popular holiday pies. When I wrote my book Grain and Fire: A History of Baking in the American South, I was surprised at how new the pecan pie as we know it (hereafter PPAWKI) is. It is...