Preheat oven to 500°F (260°C).
Microwave potatoes according to package directions. Place on a baking sheet and lightly press down on each potato with a spatula. Add a spoonful of marinara sauce to each one, sprinkle with cheese and add one slice of pepperoni.
Bake for 5-8 minutes, or until cheese is melted. Remove from oven, garnish with fresh parsley and enjoy!