12 ounces frozen spinach, defrosted and squeezed of all liquid
8 ounces canned or frozen & defrosted quartered artichokes, chopped
8 ounces mascarpone cheese
6 ounces smoked mozzarella, shredded
8 ounces plus 1 tablespoon shredded Parmesan or Pecorino Romano cheese
Preheat the oven to 425 degrees. Place a rack in the center of the oven.
Carve out the center of the loaf to create a deep well, being careful not to pierce through the bottom. Cube the portion of the bread that was removed. Place the loaf and cubes onto a foil or parchment-lined sheet tray. (If you wish, you can cut the sides of the bread adjacent to the well into a cross-hatch pattern for easy pull-apart pieces later.) Drizzle the inside well of bread and the cubes with olive oil. Season with salt and pepper. Bake for 10 to 12 minutes until crispy. Remove the cubes from the tray and set aside.
In a medium saucepan over medium heat, drizzle olive oil into the pan. Add the garlic and cook for 1 minute until fragrant. Add the spinach, artichokes, mascarpone and mozzarella cheeses and 8 ounces of Parmesan. Stir occasionally until the cheese is melted, 10 minutes. Season to taste with salt and pepper.
Pour the melted spinach-artichoke dip into the well of the toasted bread loaf. Sprinkle with the remaining tablespoon of Parmesan cheese. Return the loaf to the oven for an additional 7 to 10 minutes until bubbling.