01 - Preheat your oven to 375°F. Line a standard baking sheet with parchment paper to prevent sticking.
02 - In a large mixing bowl, combine the shredded cooked chicken breast, softened cream cheese, ranch dressing, buffalo wing sauce, shredded mozzarella cheese, and shredded cheddar cheese. Mix thoroughly until all components are well blended and uniformly distributed.
03 - Carefully slice the top third off the French bread loaf lengthwise. Using a serrated knife, gently hollow out the soft interior of the bread, leaving an approximate 1/2-inch thick shell. Reserve the removed bread for another culinary purpose.
04 - Generously spoon the prepared buffalo chicken dip mixture evenly into the hollowed French bread loaf. Place the stuffed loaf onto the prepared baking sheet.
05 - Bake the stuffed bread in the preheated oven for 25 to 30 minutes, or until the filling is bubbly and the bread achieves a golden-brown color.
06 - Remove the baked loaf from the oven and allow it to cool for approximately 5 minutes. Before serving, sprinkle with chopped green onions and fresh parsley, if desired.
07 - Slice the warm buffalo chicken dip stuffed bread into portions and serve immediately.