Mom has made this every thanksgiving for as long as I can remember. It carries on a Southern tradition from my mother's side of very sweet sweet potatoes. "Yams" in the US are not true yams, but simply dark colored sweet potatoes. True yams are white, starchy, and not sweet, and will not work in this recipe.
Ingredients:
2 c raw or dark brown sugar
2 sticks butter (1 cup)
1/2 tsp salt
4 sweet potatoes or yams
Cut sweet potatoes into 1 inch chunks. Microwave for 10 minutes. In a deep pan, melt butter. Add sugar and salt. Mix until lumps disappear. Add sweet potatoes and mix to combine. Cook uncovered on low heat, simmering, until the mixure begins to stick to the bottom of the pan. (about 30 minutes) Turn off heat, cover, and let sit until room temperature, or overnight.