Twice-Baked Sweet Potatoes

Everyone's heard of twice-baked potatoes. But as this Cook's Illustrated recipe shows, you can fancy this classic up a little, while adding some hidden nutrition. This would be a great Thanksgiving dish, too!
Twice-Baked Sweet Potatoes With Shallot And Parmesan Topping
Serves 6
INGREDIENTS
4 small sweet potatoes, unpeeled, each pricked with a fork in 3 places
3 tbsp unsalted butter, plus 2 tbsp melted butter
2 shallots, sliced thin
2 slices hearty white sandwich bread, crusts removed, cut into 1/8 inch pieces
1/2 cup grated Parmesan
1 tsp minced fresh thyme
Salt and pepper
1 large egg, lightly beaten
INSTRUCTIONS
1. Place potatoes in shallow baking dish. Microwave until skewer glides easily through flesh, 9 to 12 minutes, flipping potatoes every 3 minutes. Let potatoes cool for 10 minutes. Adjust oven rack to middle position and heat oven to 425 degrees.
2. Melt 3 tablespoons butter in a 10-inch skillet over medium heat. Add shallots and cook, stirring occasionally, until softened, 2 to 5 minutes. Transfer shallots to bowl. Add bread pieces, 1/4 cup Parmesan, thyme, 1/4 teaspoon salt, and 1/4 teaspoon pepper to bowl with shallots. Toss to combine.
3. Halve each potato lengthwise. Using spoon, scoop flesh from each half into second bowl, leaving about 1/8- to 1/4-inch thickness of flesh. Place 6 shells cut side up on wire rack set in rimmed baking sheet (discard remaining 2 shells). Bake shells until dry and slightly crispy, about 10 minutes.
4. Meanwhile, mash potato flesh with ricer, food mill, or potato masher until smooth. Stir in egg, 2 tablespoons melted butter, 1/2 teaspoon salt, and remaining 1/4 cup Parmesan. Remove shells from oven and reduce temperature to 375 degrees. Divide mashed potato mixture evenly among shells. Top each filled shell with bread mixture. Bake until bread is spotty brown, about 20 minutes. Let cool for 5 minutes before serving.