Preheat oven to 350 degrees

Add meatballs and cover with marinara sauce to a medium sauce pan over medium heat. Cover the pot and cook for several minutes until meatballs are completely thawed.

Place hotdog buns in a baking dish

After the meatballs are fully thawed remove them one at a time and cut them in half, place 3 halves in each bun. Continue until all buns are filled. (you may have a few left over meatballs)

Drizzle a little extra sauce over each sub

Topped each sub with a handful of mozzarella cheese

Bake in oven for 10 minutes or until cheese is melted