Making a meatball sub is straightforward, especially when following these steps:

1. Prepare the Meatballs: Cook the frozen meatballs in marinara sauce in a saucepan until heated through. This allows the flavors to meld and ensures the meatballs are juicy and flavorful.
2. Prepare the Rolls: Keep 3 rolls connected for each sub. Hollow out the centers to make room for the meatballs. Mix the melted butter with garlic powder and Italian seasoning, then brush the mixture onto the rolls. Bake at 350°F (175°C) for 5 minutes to give them a slightly crispy texture.
3. Assemble the Subs: Fill each roll with the cooked meatballs and marinara sauce. Top generously with grated mozzarella cheese.
4. Final Touch: Bake the assembled subs at 350°F (175°C) for an additional 5 minutes or until the cheese is melted to perfection.