Preheat your oven to 350°F (175°C).
Cut the tops off the garlic bulbs and shallots, then drizzle them with olive oil. Wrap them in foil and place them in the oven. Roast for 1 hour until softened and fragrant.
Once roasted, remove from the oven and allow the garlic and shallots to cool slightly. Squeeze the roasted garlic cloves and shallots into a bowl, discarding the skins. Reserve the garlic oil left in the foil for later use.
In the same bowl, add the softened butter, Parmesan cheese, and parsley. Season with salt and pepper to taste. Mix everything together until well combined to create your garlic butter mixture.
Slice the Italian baguette in half lengthwise. Spread the garlic butter mixture evenly on both halves of the bread.
Top the buttered bread with shredded mozzarella cheese, spreading it evenly across both halves.
Place the bread on a baking sheet and bake in the preheated oven for 15-20 minutes, or until the cheese is melted and golden brown.
Once out of the oven, sprinkle with additional parsley for garnish and drizzle the reserved garlic oil over the top for extra flavor.
Slice and serve warm, enjoying the cheesy, garlicky goodness!
