A casserole of candied yams or sweet potatoes with marshmallow topping is traditional on many Thanksgiving tables, but I wanted to give this classic accompaniment an updated twist, so I have made it with a pecan streusel topping. For years, I have taught Thanksgiving classes around the country, and every time I demonstrate this recipe and the students sample the dish, they tell me these sweet potatoes are the best they have ever tasted. They are lightened with eggs and enriched with butter and brown sugar—but the pecan streusel topping is what makes this casserole divine. Hot from the oven, the meltingly lush topping is browned to a caramelized crisp at the edges.
5 pounds dark-orange-fleshed sweet potatoes scrubbed
1/2 cup (1 stick) unsalted butter
3/4 cup firmly packed dark brown sugar
3/4 cup milk warmed
3 large eggs lightly beaten
3/4 cup pecans coarsely finely chopped
1/2 cup all-purpose flour
1/2 cup firmly packed dark brown sugar
3/4 teaspoon cinnamon ground
1/2 teaspoon nutmeg freshly grated
1/2 teaspoon kosher or sea salt
1/2 cup (1 stick) unsalted butter melted
1/2 cup heavy (whipping) cream
Position a rack in the center of the oven and preheat to 350°F. Pierce each potato several times with a fork and place them in a baking pan. Bake until very tender when pierced with a fork, 1 1/4 to 1 1/2 hours. Set aside until cool enough to handle. Leave the oven on.
In a small saucepan over medium heat, melt the butter. Add the brown sugar and Cook, stirring, until the sugar is dissolved and the mixture is bubbly hot. Set aside. Cut the potatoes in half, scoop the flesh into a large bowl, and discard the skins. Mash with a potato masher, or pass the potatoes through a ricer or food mill held over a bowl. Stir the butter mixture into the mashed potatoes. Add the milk and stir until incorporated. Whisk in the eggs until well combined.
Butter a 3-quart oval gratin dish or an 11-inch round oven-to-table casserole. Spread the sweet potato mixture evenly in the casserole. Set aside while making the topping. Raise the oven temperature to 375°F.
To make the streusel topping, in a bowl, combine the pecans, flour, sugar, cinnamon, nutmeg, and salt. Stir in the melted butter and cream. Spread the streusel topping evenly over the sweet potatoes.
Bake until the potatoes are hot throughout and the topping is nicely browned and crisp, about 40 minutes. Serve immediately.
The whipped sweet potatoes and the topping can be made up to 1 day in advance. Cover and refrigerate in separate containers. Remove the potatoes and topping 2 hours before you plan to bake the casserole. Warm the topping and spread it over the potatoes just before baking.