My late dearly beloved mother-in-law, Jeanne, passed this recipe to me early in my marriage, around 1971 or so. It's one of my favorite covered dish offerings, so I often double the recipe & put marshmallows on 1/2 of the sweet potatoes. (The photo at left shows this very dish.) These sweet potatoes are winners either way! =^..^=
Spray casserole dish with cooking spray & preheat oven to 325 degrees F.
Arrange sweet potatoes in casserole dish. Sprinkle with brown sugar, salt, and cinnamon. Dot with butter pieces.
Bake at 325 degrees F. for about 40-45 minutes, until sweet potatoes are heated through and syrup is bubbly.
If desired, add marshmallows and return to the oven until marshmallows have melted and browned. Check after 4 minutes or so to gauge browning time.
NOTE: If you double the recipe, use a 13 x 9" pan or baking dish.
NOTE: If other foods are baking at 350 degrees F. & you want to bake this at the same time, cut the baking time (check after 25 minutes)for the sweet potatoes, then check the marshmallows after about 3 minutes.