Preheat the oven to 375°F (190°C) and prepare a baking sheet with parchment paper for a non-stick surface.
Gently unroll the pizza dough over the parchment, stretching it evenly without tearing.
Arrange the mozzarella cheese along the center of the dough, leaving about 1 inch of space at each end and keeping roughly one-third of the dough uncovered on both sides.
Evenly layer the shredded chicken, chopped bacon, and ranch dressing over the cheese, ensuring the filling remains centered.
Fold one unfilled side of the dough over the filling, then roll it tightly into a log shape. Press and pinch the seams and ends firmly to enclose the contents.
In a small bowl, whisk the beaten egg with 1–2 tablespoons of water to prepare an egg wash. Position the dough seam-side down on the baking sheet.
Brush the surface of the dough with the egg wash, then sprinkle with ranch seasoning and chopped parsley. Using a sharp knife, create small slits across the top to allow steam to escape during baking.
Bake in the preheated oven for 20–25 minutes, or until the crust develops a rich golden hue and turns crisp.
Remove from the oven and allow the stromboli to rest for several minutes before slicing. Serve with additional ranch dressing for dipping, if desired.
