- Preheat the oven to 400°F (200°C). Bake sweet potatoes for 1 hour or until very tender. Cool until easy to handle; peel and discard skins. Mash the potato flesh until very smooth. Beat in sour cream and garlic until well combined. Season with salt and pepper; adjust to taste. Transfer to a greased 2-inch (5 cm) full-size hotel pan.
- Place parsley in a food processor; pulse until finely chopped. Add the bread, pecans and Parmesan; pulse until well combined but still chunky. Toss with butter until well coated. Sprinkle evenly over the sweet potato mixture. (Reserve at this point in the refrigerator for up to 3 days).
- Bake in a preheated 350°F (180°C) for 45 minutes (60 minutes from the refrigerator) or until browned and heated through.