Heat a large skillet over medium-high heat. Simmer the frozen meatballs with about a 1/2 cup of water. Cover and stir the meatballs occasionally until no longer frozen, and are warmed all the way through (about 7-10 minutes.) Add the jar of marinara sauce, reduce heat to medium and bring the sauce a meatballs to a simmer. Once simmering, remove from heat.

On the lined baking sheet, place the entire package of rolls still all in one large piece/loaf. Using a serrated knife, slice the entire loaf of rolls horizontally, half way up the sides of the rolls. Remove the top half section of the rolls.

Reserving the heated marinara sauce, place a cooked meatball on each individual roll section (24 meatballs.) Cover the meatballs with the shredded mozzarella and Parmesan cheeses. Top the cheese covered meatballs with the top section of the rolls.

In a small dish or cup, combine the melted butter, garlic and Italian herbs. Brush the tops of the rolls with the butter mixture. Then, sprinkle the tops of the rolls with the grated Parmesan cheese.

Bake at 425 degrees for 8-10 minutes or just until the cheese are melted. Watch the bread so it doesn't over-brown.

Remove from oven and serve right away. Serve with reserved marinara sauce for dipping.