Buttermilk Pie, a very popular American pie variety, mostly in the Southern United States, is a traditional preparation primarily in a custard-like base. Buttermilk pie is often made with a pastry crust, which is filled with a mix consisting of such ingredients like eggs, buttermilk, butter, sugar, eggs etc. Somewhat resembling the cheese pies and pecan pies, buttermilk pie is almost a signature dessert for many, when flavored with vanilla and other similar flavorings. Some varieties of buttermilk pies even take in lemon extract or zest, which is said to give the pie the subtle tangy flavor. The old fashioned buttermilk pie also had cream of tartar in the pie mix, which rendered the pie truly flavorful.