Preheat the oven to 375°F (190°C). Line a baking tray with either parchment paper or aluminum foil for easier cleanup.
In a mixing bowl, combine the softened butter with the minced garlic, chopped parsley, oregano (if using), and a small pinch of salt. Stir until thoroughly blended into a smooth garlic butter spread.
Lay the bread halves cut-side up on the prepared baking sheet. Evenly distribute the garlic butter mixture across the surfaces of both bread halves.
Generously scatter the mozzarella cheese over the buttered bread, followed by an even layer of Parmesan.
Transfer the baking tray to the oven and bake for approximately 12 to 15 minutes, or until the cheese is fully melted and bubbling.
For a crisp and golden cheese topping, switch the oven setting to broil and toast the bread for an additional 1 to 2 minutes. Keep a close eye to prevent burning.
Remove from the oven, slice into portions, and serve immediately. Garnish with additional fresh parsley, if desired.