Preheat the oven to 400 degrees Fahrenheit and line a baking sheet with foil or parchment paper.
In a large mixing bowl, stir together the beef, egg, breadcrumbs, parmesan cheese, garlic powder, Italian seasoning, salt, pepper and fresh parsley. Mix with your hands or a wooden spoon until just combined (do not over mix).
Take approximately 2 tablespoons of the meat mixture. Roll it into a ball and place a piece of the cheese into the center of the ball.
Place the prepared meatball on the baking sheet. Continue this process until all the meat mixture and cheese are used.
Bake for 15-20 minutes (flipping halfway) until the meatballs are no longer pink in the center. Watch them closely so that the cheese does not spill out while they are cooking.
Heat the marinara sauce in a small saucepan.
Serve the meatballs topped with the marinara sauce and enjoy!
Notes
Refrigerate the leftovers in an airtight container for up to 5-7 days.