Serves 8 to 12
6 tablespoons light brown sugar
1/4 cup unbleached all-purpose flour
4 tablespoons unsalted butter (very cold), cut into 1/4-inch pieces
1/2 cup chopped pecans
3 pounds sweet potatoes (about 6 medium potatoes), peeled, halved lengthwise, and halves cut crosswise into 1/4-inch slices
6 tablespoons unsalted butter , melted
2 tablespoons honey
3 tablespoons molasses
1 tablespoon grated fresh ginger or 1 teaspoon powdered ginger
3/4 teaspoon table salt
1/4 teaspoon cayenne pepper
1 1/2 tablespoons cornstarch
1. For the Topping: Whisk brown sugar and flour in small bowl. Add butter, and toss to coat; pinch between fingertips until mixture is crumbly and resembles coarse cornmeal. Stir chopped pecans into mixture; cover and refrigerate until ready to use.
2. Adjust oven rack to middle position and heat oven to 375 degrees. In large pot or Dutch oven of boiling water, parboil sweet potato slices over high heat until they are bright orange and the point of a paring knife easily pierces but does not break apart a few slices, 4 to 5 minutes. Drain potatoes well and turn into buttered 13-x 9-inch baking dish.
3. Whisk melted butter, honey, molasses, ginger, salt, and cayenne in small bowl; set aside. Mix cornstarch with 2 tablespoons cold water in small bowl until totally smooth, then whisk into butter mixture; pour over sweet potatoes and toss to coat well.
4. Cover dish tightly with foil and bake until liquid is bubbly, about 50 minutes. Remove foil, stir potatoes gently, sprinkle cold topping mixture over potatoes, and bake until topping is crisp and dark golden brown, about 20 minutes longer. Cool slightly and serve hot or at room temperature.