How to Make It
Preheat the oven to 400°. Line a large baking sheet with aluminum foil.
Rub the potatoes with the olive oil and season with 1/2 teaspoon of the salt and 1/8 teaspoon of the pepper. Put the potatoes on the baking sheet and bake until fork-tender, 1 hour to 1 hour and 10 minutes. Let the potatoes sit until cool enough to handle.
Cook the bacon in a medium skillet over moderate heat, stirring occasionally, until crisp and the fat is rendered, 5 to 6 minutes. Drain on paper towels.
Peel 1 potato completely, discarding the skin. Place the pulp in a large bowl. Cut the top quarter from each of the remaining 4 potatoes and using a spoon, scoop the pulp from the potatoes into the bowl, leaving a 1/4-inch layer of pulp on the skin. Return the potato shells to the baking sheet.
Using a handheld masher, mash the potato pulp until smooth. Add 1 cup of the cheese, the sour cream, butter, bacon, chives, and the remaining 1 1/4 teaspoons of salt and 1/4 teaspoon plus 1/8 teaspoon of pepper and mash until smooth. Spoon the potato mixture back into the potato shells, top with the remaining cheese and bake until hot and the cheese is melted, about 15 minutes. Serve hot.