Preheat the oven to 350 degrees F.
In a small bowl mix the butter, garlic, parsley and Parmesan together.
Cut the bread in half lengthwise and smear the butter from edge to edge.
Place the two halves back together, wrap the bread in foil and bake on the middle oven rack 12 minutes.
Take the bread out and heat the broiler.
Unwrap the bread and cut into 1-inch wide strips with a serrated knife.
Place on the baking sheet butter side up and sprinkle with mozzarella cheese.
Broil about 2 minutes with the oven door cracked open until the cheese melts and turns lightly golden.