There was a mom and pop pizza place in Lewisville, that imported them from St. Louis, but it has since closed. The next best thing that I have found is at iFratelli at 635 / MacArthur. They come fried with a veal and beef mixture. Hopefully you'll get a few other suggestions.
It's been a long time since I have been here http://www.5thstreetpizza.net/5th-Str.... They made a just okay St. Louis style pizza. There was a much better place but it did not make it for some reason.