Roasted Sweet-Potato Casserole with Praline Streusel

Preheat oven to 350 degrees F. Using a fork, prick sweet-potatoes all over, then roast on a baking pan until soft, about 1 hour. Let cool, then peel and discard skins. Place sweet potato flesh in a large bowl and mash until smooth. Add orange juice and zest. Stir in granulated sugar, eggs, 2 tablespoons butter, baking powder, 1 1/2 teaspoons vanilla, and 1 teaspoon salt until combined. Transfer sweet-potato mixture to a buttered 3-quart casserole dish. (At this point, the casserole can be covered and refrigerated overnight.)

In a large saucepan over medium heat, combine pecans, brown sugar, 1/8 teaspoon salt, and remaining butter and vanilla and bring to a boil. Cook for 2 minutes more, then pour over sweet-potato mixture. Bake until bubbly, 40 to 45 minutes.