Preheat the oven to 400oF and roast the sweet potatoes on a parchment-lined baking sheet until very tender. The timing depends on the size of the sweet potatoes, anywhere from 30 to 60 minutes. If there are multiple sweet potatoes, space them out on the sheet pan. Alternatively, peel the sweet potatoes, cut into chunks, and steam until tender. (This will be faster but they won't be as sweet.)
Remove the skin, place the cooked sweet potatoes in a food processor or high-speed blender with all the remaining ingredients, and process until perfectly smooth. A Vitamix will achieve the most puddinglike consistency. Taste and adjust the sweetness. Serve at room temperature or chill until cold. Top with your desired toppings. Can be made up to 3 days in advance.