We're from the deep South and we've always eaten lots of sweet potatoes and my mom's sweet potato pie is yummy. We do as so many others and bake our potatoes. I think they have a richer taste if they're baked with the peeling on and a little oil or shortening rubbed in. We eat them plain with butter and it's like dessert. I agree with the lady who said that most recipes for the s. potato casseroles are too sweet for my taste. Just like simple foods.
For my mom's pie, she just mashes the baked potatoes and adds sugar to taste, some butter or margarine and a little cinnamon or not. Again, I like simple foods and the potatoes are so rich and sweet that they don't need lots of spice and only a little sugar added to make the pie. Yummy.
She doesn't put eggs in her pie because that makes it more custardy. Simple, huh!