For the sweet potato mash:

1. Place sweet potatoes in a large pot and cover by at least 2-3 inches of water. Bring to a boil over medium-high heat. Boil until completely tender (potatoes will pierce easily with a fork). Drain sweet potatoes.
2. Transfer cooked sweet potatoes to a large mixing bowl. Add milk, butter/oil, syrup, salt, vanilla, and egg/egg sub.
3. Mash with a potato masher or fork until no lumps remain. If needed, add 2-3 Tbsp additional milk if your mixture seems too thick.
4. Pour mash into an 8×8 or 2 quart baking dish and smooth the surface. (You can make the sweet potato casserole up to this point the day before Thanksgiving, if desired. Simple cover the baking dish and refrigerate)

For the topping:

1. When ready to bake the sweet potatoes, preheat the oven to 375 degrees F and make the topping. In a medium bowl, combine pecans, butter/oil, syrup, cinnamon, and salt.
2. Sprinkle pecan streusel topping over the sweet potato mash.
3. Cover the dish with foil and bake 20 minutes at 375 degrees.
4. Remove foil and bake another 20-25 minutes. If pecans begin to brown too quickly, simply cover with foil again.
5. **If you’ve got multiple things in the oven (like on Thanksgiving), allow yourself some extra time. If your oven is set to a lower temperature or full of other dishes, you’ll need to bake this closer to an hour. Be sure to watch your pecans (I only remove the foil when there’s about 20 minutes to go).