Preheat oven to 350°F. Line rimmed baking sheet with parchment paper.
In a small bowl mix together butter, garlic, parsley, basil and salt.
Slice bread in half lengthwise and place on prepared baking sheet, cut sides up. Spread the butter mixture evenly on the bread halves. Sprinkle with parmesan then mozzarella cheese.
Bake for 10 to 12 minutes until the cheese is melted and bread edges are starting to toast.
Turn on oven broiler and broil on HIGH for 1 to 2 minutes until cheese is bubbling and starting to brown in spots. Remove pan from oven and dust with remaining parmesan. Garish with extra parsley and red pepper flakes if desired. Cut bread into pieces and serve hot.