Preheat your oven to 375°F
Slice the sourdough bread in a crisscross pattern, making vertical and horizontal cuts but ensuring the bottom of the loaf stays intact (like a grid). Be careful not to cut all the way through the loaf; you want to keep the bottom connected so the bread stays whole.
1 loaf of sourdough bread
In a small bowl, combine the melted butter, minced garlic, parsley, salt, and pepper. Mix well until everything is fully incorporated.
1/2 cup unsalted butter, 6 cloves garlic, 2 tablespoon fresh parsley, Salt and pepper
Use a spoon or pastry brush to generously drizzle the garlic butter mixture into all the cracks and crevices of the bread.
Sprinkle both the mozzarella and Parmesan cheese into the cracks, making sure the bread is well-filled with the cheese.
2 cup shredded mozzarella cheese, 2/3 cup grated Parmesan cheese
Wrap the bread loosely in aluminum foil and place it on a baking sheet.
Bake for 25 minutes, then open the foil and bake for an additional 8-10 minutes, until the cheese is melted and bubbly and the bread is golden brown.
Once baked, remove the bread from the oven and let it cool for a few minutes. You can brush the bread with more melted butter if you want it to have that beautiful shine.
Serve warm and pull apart to enjoy the gooey, cheesy goodness!