In a large bowl, combine breadcrumbs and milk, letting them soak for about 5 minutes. Add ground beef, egg, Parmesan, garlic, Italian seasoning, salt, pepper, and parsley. Mix gently until everything is just combined.

Roll the mixture into about 24 golf ball-sized meatballs, roughly 1½ inches in diameter. Create slightly larger indents in the center of each meatball to hold the 'eyeballs' later.

Place the formed meatballs on a lined baking sheet. Bake in a preheated oven at 400°F (200°C) for 20-25 minutes, or until cooked through and nicely browned.

Pat the mozzarella balls dry with a paper towel. Cut each green olive in half and press each half onto a mozzarella ball to create the 'pupil'.

In a skillet, gently warm the marinara sauce over medium heat. Add the freshly baked meatballs and simmer for about 5 minutes. Press the mozzarella 'eyeballs' into the meatballs.

If desired, use toothpicks dipped in red gel food coloring to draw creepy veins on the cheese.

Carefully arrange your Eyeball Meatballs on a serving dish with extra marinara sauce for dipping, and serve immediately.