Preheat oven
Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper.
Prepare the bread
Slice the bread lengthwise and hollow out some of the inside to create space for the filling.
Make the filling
In a bowl, combine chicken, bacon, ranch seasoning, mozzarella, cheddar, and optional cream cheese. Mix well.
Stuff the bread
Fill the bread generously with the chicken bacon ranch mixture.
Bake
Place on the baking sheet and bake uncovered for 20–25 minutes, until cheese is melted and bubbly.
Serve
Let cool slightly, slice, and serve warm.