½cupfinely chopped pecansoptional, but highly recommended
4tablespoonsunsalted butter, softened
Preheat oven to 350°F. Lightly grease an 8x8 baking dish and set aside.
Peel and chop the sweet potatoes (you should have around 10 cups). Place in a large pot, cover with water, and boil until tender (about 7 minutes, depending on the size). Drain well, return to the pot, and mash the potatoes. You should have around 4 cups of mashed sweet potatoes.
Whisk granulated sugar, brown sugar, eggs, cream/milk, melted butter, vanilla and salt. Add the egg mixture and the mashed sweet potatoes to a large mixing bowl or the bowl of a food processor. Mix with a hand mixer (or process with a food processor) until the mixture is smooth and combined. Pour the potatoes into the baking dish.
Combine brown sugar, flour, cinnamon, salt, and pecans (I use a fork). Add softened butter and use your fingers to blend the butter into the flour mixture until well combined (it should resemble wet sand).
Sprinkle the topping over the sweet potatoes and bake in the middle of the oven for 30-40 minutes, until the topping is golden brown.
*Some grocery stores might have these potatoes labeled as YAMS. Make sure you purchase sweet potatoes/yams with orange flesh and pinkish brown skin. Scrape the skin a little to see the color of the flesh, if necessary.MAKE AHEAD
Prepare the sweet potatoes and place in the baking dish. Cover tightly and refrigerate for up to 24 hours.
Prepare the topping (do not add it to the sweet potatoes). Cover it tightly and refrigerate for up to 24 hours.
Bake: Cover the sweet potatoes with foil (no topping yet) and heat in a 350°F oven for about 25 minutes, until warmed all the way through. Remove the foil and sprinkle the topping over the sweet potatoes. Bake for 20-30 more minutes (uncovered), until the topping is golden brown.