Grandmother's Candied Sweet Potatoes

These are almost overkill, they're so sweet--which begs the question: can something be too sweet? I've never made these (but have eaten plenty of them at points in my life!). I'm going to type this up as I have it from my grandmother:

Boil potatoes in skins until done. Drain and peel. Slice into baking dish. In a small sauce pan, place 3/4-1 c. sugar, sufficient water to stir the sugar (about 1/2-3/4 cup) and about 1/3 stick butter. Bring to boil and boil gently about 15 minutes. Pour over potatoes. Bake uncovered 1 hour at 350 degrees.