Preheat the oven to 375°F (190°C) and prepare a baking sheet by lining it with parchment paper.
Unroll the refrigerated pizza dough and gently stretch it out over the parchment paper, ensuring an even layer.
Evenly distribute the mozzarella cheese along the center of the dough, leaving approximately 1 inch of space at each end and about one-third of the dough free on either side.
Layer the shredded rotisserie chicken, crisp bacon, and ranch dressing over the cheese, maintaining the central alignment.
Fold one of the empty sides over the filling, then roll the dough tightly into a log, resembling a cinnamon roll. Ensure the seams and ends are pinched together firmly to secure the filling.
In a small bowl, whisk the beaten egg with a tablespoon or two of water to create an egg wash. Carefully position the dough seam-side down on the prepared baking sheet.
Brush the surface of the stromboli with the egg wash, then sprinkle it with ranch seasoning and freshly chopped parsley. Make a few slits across the top of the dough to allow steam to escape during baking.
Place the stromboli in the preheated oven and bake for 20–25 minutes, or until the exterior is golden brown and crisp.
Remove from the oven and allow to cool slightly before slicing. Serve with additional ranch dressing for dipping, if desired.