Preheat oven to 350°F. Set aside a baking sheet. Prepare a large piece of heavy duty foil, Spritzed lightly with cooking spray.
Use a sharp knife to cut 12 diagonal slices through bread without cutting all the way to the bottom. (Yield may be less depending on length of bread)
In a small bowl, whip together butter, Parmesan, parsley, basil, rosemary and salt.
Spread each slice with garlic and herb butter reserving 1 Tbsp to spread on top. Place two half pieces of cheese into each cut. Spread remaining garlic and herb butter over top and sides of loaf.
Place onto foil and bring edges up to seal. Place onto baking sheet.
Bake 25-30 minutes or until cheese is melted and bread is toasty. Open foil and broil top, if desired. Serve immediately.