When bacon is done, Place remaining bacon drippings into a skillet. Heat to medium and cook shallots until translucent. Add fresh spinach leaves to the skillet and cover. Cook for about 3-4 minutes, stirring occasionally until all spinach has reduced in size. Once cooked, turn off the heat and leave semi-covered.
Mash the potatoes in the bowl then add sour cream, cream cheese then spinach mixture. 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!