Preheat the oven to 400 degrees. Rub the clean potatoes with a bit of olive oil then sprinkle them with salt evenly. Place into the oven and bake until tender, about 1 hour. Remove from the oven and let them cool. Slice in half lengthwise then scoop out the potato filling. Rub a bit more olive oil on the outside and inside of the potato halves then season with a bit more sea salt. Place them, skin side up, on the baking sheet and bake for 4-5 minutes or until crispy.
Remove from the oven and spoon in some marinara sauce then top with mozzarella cheese, mini pepperoni slices, and parmesan.
Place back into the oven and bake for 5-7 minutes or until the cheese is gooey. Remove from the oven and sprinkle the top with chopped parsley. Serve immediately. Enjoy.