Preheat oven to 350°
Take a piece of foil and place whole garlic cloves in it, coating With a generous amount of olive oil. Wrap tightly. Bake until done, 20 minutes to 1/2 hour. Cloves will be done when sweet smelling, soft and golden brown.
Split bread lengthwise. Remove excess dough.
Mash roasted garlic with all other ingredients except cheeses. Spread cut surfaces of bread with butter mixture. Sprinkle with parmesan and layer bottom half with mozzarella.
Press halves together and wrap tightly in foil. Bake at 350° until outer crust is crispy and cheese is melted, about 15 minutes.
Let cool slightly and cut into thick horizontal slices.