Preheat oven to 350°F (175°C).
Using a sharp serrated knife, make diagonal cuts through the bread, creating a crosshatch pattern, but do not cut all the way through the bottom.
Mix melted butter and minced garlic together in a small bowl.
Gently separate the bread sections and evenly drizzle the garlic butter between the cuts.
Stuff the grated cheddar and mozzarella cheeses between the cuts.
Wrap the bread in foil and place on a baking sheet.
Bake for 15 minutes, then unwrap the foil and bake for an additional 5 minutes, or until the cheese is melted and bubbly.
Sprinkle with fresh parsley before serving.