Preheat oven to 350 F.
Butter a 2-quart casserole dish.
In a stock pot or Dutch oven, place sweet potato slices and cover with water. Bring to a boil over medium high heat, and cook for 8 to 10 minutes until tender. Drain pat dry. Arrange potato slices in prepared baking dish.
In a small sauce pan, combine cranberries, onion, water, honey, orange zest, orange juice, and cinnamon. Bring to a boil over medium heat. Reduce and simmer 15 to 20 minutes until cranberries pop. Add butter, and stir until melted into sauce.
Pour cranberry mixture over potatoes. Bake in preheated oven, uncovered, for 20 to 30 minutes until glazed and bubbly. Serve hot.