Tourtes are covered pies in France. They are not called tourtes by virtue of their roundness or their contents. Sweet or savory, tourtes are pies with an upper crust. No matter that in Germany they are round sweet cakes with nuts & cinnamon, no matter that the origin of the word comes from the latin torta, round. Escoffier said so, and so it is. No matter, we still see exceptions here and there, but ask any booksmart gourmand or gourmet, and they may have a thing or two to say if you don't include that upper crust! Anything different and it's a tarte, they'll say. By my twisted logic, I think tourtes are an older, wiser, more thoughtful, slightly more modest version of the tarte.