1. Preheat the oven to 375° F. Coat a rimmed baking sheet with cooking spray. Place the potatoes on the baking sheet and pierce them all over with a fork.
2. Bake for 40 to 45 minutes, or until they’re tender. Let the potatoes stand until cool enough to handle, then cut each in half lengthwise. Carefully scoop out the insides, leaving about 1/8-inch-thick shells. Save the potato insides for another use, or discard.
3. In a medium bowl, combine the remaining ingredients to make the spinach mixture.
4. Turn the oven temperature to broil. Broil the empty potato skins for 4 to 6 minutes, or until edges are brown. Spoon the spinach mixture evenly into the skins. Broil for 3 to 4 minutes, or until warmed through and beginning to brown. Serve warm.

Recipe adapted from Mr. Food Test Kitchen Guilt-Free Comfort Favorites by Howard Rosenthal, available May 2018.