Bake sweet potatoes on the middle rack of oven set to 350˚. On rack directly below middle one, place separated strips of bacon on a baking sheet. Bake bacon for 40 minutes. Bake sweet potatoes for 55-60 minutes.
When bacon is done, remove from baking sheet and place on a paper towel to absorb grease. Place remaining bacon drippings into a skillet. Heat to medium and cook shallots until translucent. Add fresh spinach leaves to skillet and cover. Cook for about 3-4 minutes, stirring occasionally until all spinach has reduced in size. Once cooked, turn off heat and leave semi-covered.
Remove potatoes from oven when they are tender to touch. Cut in half and scrape insides into a large bowl leaving a thin layer of potato on the skins. Optional: For extra crispy skins, brush the the skin side of each potato with bacon drippings. Place potatoes skin-side down back on the baking sheet.
Mash the potatoes in the bowl then add sour cream, cream cheese then spinach mixture. Stir well and salt lightly to taste. (Don't forget the bacon will add saltiness)
Stuff sweet potato skins with spinach mixture. Top each with a few sprinkles of mozzarella cheese. Chop bacon then add bacon bits on top of cheese. Bake for another 10-12 minutes or until cheese is melted. Enjoy warm and fresh out of the oven!