Savory twice baked sweet potatoes

For a less formal but equally appealing presentation, you can spoon rather than pipe the filling into the shells.

3 medium sweet potatoes (1Ë™ to 2 pounds), scrubbed well

4 ounces smoked bacon, sliced

2 tablespoons dark-brown sugar

3 tablespoons unsalted butter, softened

2 small shallots, finely minced

1 teaspoon minced fresh rosemary, plus more for garnish

1 large egg

2 tablespoons heavy cream

2 ounces Gruyere cheese, finely grated, plus more for garnish

Coarse salt and freshly ground pepper

• Preheat the oven to 400F. Place the sweet potatoes on a parchment-lined baking sheet; bake until tender when pierced with a paring knife, about 45 minutes. Remove from the oven; let cool slightly.
• Line a rimmed baking sheet with foil; fit with a wire rack. Arrange the bacon strips on the rack, and sprinkle with the brown sugar. Cook until well glazed and crisp, 12 to 15 minutes. Remove from the oven; let cool slightly, and roughly chop. Set aside.
• Melt 1 tablespoon butter in a small skillet over medium heat. Add the shallots; saute until soft and fragrant, about 2 minutes. Add the rosemary, and cook 1 minute more. Remove from heat, and set aside.
• Slice each potato in half lengthwise. Carefully scoop out the flesh, leaving about a 1 / 4 -inch border all around the potato halves; set the halves aside on a baking sheet.
• Place the flesh in the bowl of an electric mixer fitted with the paddle attachment. Add the remaining 2 tablespoons butter and the reserved shallot mixture, egg, cream, and Gruyere. Mix well until combined. Season with salt and pepper.
• Transfer the mixture to a pastry bag fitted with a star tip; pipe into the reserved halves. Bake until golden, about 20 minutes. Remove from the oven. To serve, garnish with the Gruyere, rosemary, and reserved bacon.
• SERVES 6