When Lisa S. was growing up in North Carolina, she and her cousins pitched in every Thanksgiving to make this generations-old recipe. "We would throw sticks up in the pecan trees in the backyard to knock down the pecans," says Lisa. "My grandmother had fresh sweet potatoes, and my dad would crack the coconut." Lisa now lives in Winter Haven, Florida, but every year her grandmother sends her a package of pecans to top off this sweet-potato surprise.
Heat the oven to 375 degrees. In a large bowl, mix the sweet potatoes, sugar, margarine, milk, eggs, and vanilla extract until well combined. Transfer the mixture into a 2 1/2-quart baking dish.
In a separate bowl, combine the topping ingredients with a pastry cutter or your fingertips until crumbly. Distribute the topping over the sweet potatoes. Then bake the casserole for 20 minutes or until lightly browned. Serves 6 to 8.