adapted from Food Network Magazine, October 2010
4 large russet potatoes
1 large sweet potato
1/2 cup sour cream
4 tbsp unsalted butter, but into pieces and softened
2 scallions, thinly sliced
1 cup shredded sharp cheddar cheese
6 slices bacon, cooked crisp and crumbled
Pinch of mace
Kosher salt and freshly ground pepper
Extra virgin olive oil, for brushing
Preheat the oven to 400° F. Put the russet and sweet potatoes on a cookie sheet and bake for 30 minutes. Pierce each potato a few times with a fork and continue to bake until tender, 15-20 minutes for the sweet potato and 20-25 more minutes for the russet potatoes. (Test them before removing them from the oven.) Let cool slightly.
Peel the sweet potato. Transfer to a bowl and mash lightly with a fork until almost smooth. Trim a thin slice off the top of each russet potato, cutting lengthwise. Scoop most of the flesh into another bowl, leaving the shells intact. Add the sour cream and butter to the bowl and mash with a fork. Stir in the scallions, 1/2 of the cheese, mace, 1 1/4 tsp salt, and pepper to taste. Gently fold in the sweet potato.
Brush the potato skins with olive oil and season with salt and pepper. Generously fill with the marbled potato mixture and sprinkle with the remaining cheese and bacon crumbles.
Reduce the oven temperature to 375°. Place the stuffed potatoes on a baking sheet and bake until the cheese melts, 25-30 minutes.