ISO: Lambert's Cinnamon-Spiced Sweet Potatoes/Yams

I used to live north of Springfield, Missouri, and a big family tradition was a trip to Lambert's Cafe, "Home of the Throwed Rolls", everytime a relative visited us from out of state. Now we live in Colorado, and desperately miss those wonderful comfort foods of the midwest, one of which was those yummy sweet potatoes. Like none I've ever tasted before or since. I'm positive that a lot of cinnamon and butter were used in them, but beyond that, I've no clue. If you have this recipe or any others from Lambert's Cafe in Springfield and Sikeston, Missouri, I would be very much appreciative!