Cook the bacon by laying on a foil-lined cookie sheet and baking at 400 degrees for about 20 minutes. Reserve 1 tablespoon of the fat drippings.
Pierce the potatoes with a fork; microwave for 15 minutes. Remove and brush with olive oil; transfer to the oven rack and bake at 400 degrees until fully tender, about 15 minutes (more if your potatoes are on the larger side).
Meanwhile, heat 1 tablespoon olive oil plus the reserved bacon fat in a medium skillet over medium heat. Stir in the flour with a wooden spoon and cook until slightly toasted, about 2 minutes. Whisk in the milk and bring to a boil, whisking occasionally. Reduce the heat and simmer, whisking occasionally, until the sauce begins to thicken, about 6 minutes. Stir in the spinach and bacon and cook until the greens wilt and the mixture is about as thick as sour cream, 3 to 4 more minutes. Season with the cayenne and nutmeg and add salt to taste.
Slice the cooked potatoes lengthwise down the middle (but not all the way through); press in on the ends to open the slit. Drizzle ½ tablespoon oil into each potato; fluff the flesh with a fork and season with salt. Divide the spinach mixture among the potatoes and top with the shredded cheese while still hot.
Recipe by The Amiable Cooks at https://theamiablecooks.com/bacon-and-spinach-spuds/