01 - Preheat the oven to 375°F (190°C) and prepare a baking sheet lined with parchment paper.
02 - Using a serrated knife, carefully slice the bread loaf in a crosshatch pattern, ensuring not to cut through the bottom and leaving about 1/2 inch intact.
03 - In a medium mixing bowl, thoroughly combine the spinach, artichoke hearts, minced garlic, cream cheese, Alfredo sauce, Parmesan cheese, mozzarella cheese, sour cream, salt, black pepper, and crushed red pepper flakes.
04 - Gently separate the bread sections and fill the openings generously with the spinach-artichoke mixture, pressing the filling into the cuts with a spoon.
05 - Pour the melted butter evenly across the stuffed bread.
06 - Wrap the bread loosely in aluminum foil and bake for 15 minutes.
07 - Unwrap the foil and continue baking for an additional 8 to 10 minutes, or until the cheese becomes bubbly and golden brown.
08 - Remove from the oven, sprinkle with chopped parsley, and allow the bread to cool slightly before serving.