Follow these simple steps to create your incredible Homemade Costco Chicken Bake:

1. Preheat the Oven: Preheat your oven to 375°F (190°C).
2. Prepare Filling: In a large bowl, combine shredded rotisserie chicken, mozzarella cheese, softened cream cheese, ranch dressing, mixed vegetables, garlic powder, onion powder, dried thyme, salt, and pepper. Mix until well combined.
3. Roll Out Dough: On a floured surface, roll out the refrigerated pizza dough into a rectangle, about ¼ inch thick.
4. Add Filling: Spoon the chicken mixture down the center of the dough, leaving about an inch of dough clear on each side.
5. Fold in Sides: Carefully fold the sides of the dough over the filling, pinching the seams to seal the chicken bake.
6. Transfer to Baking Sheet: Place the assembled bake seam side down on a lightly greased baking sheet.
7. Brush with Egg Wash: In a small bowl, whisk together an egg and a tablespoon of water. Brush this mixture over the top of the dough for a golden finish.
8. Bake: Place the baking sheet in the preheated oven and bake for 25-30 minutes, or until the crust is golden brown.
9. Cool and Slice: Remove from the oven and let cool for about 5 minutes before slicing.
10. Serve Warm: Cut into portions and serve immediately.

These clear steps will guide you in crafting an incredible chicken bake that captures the spirit of the original Costco dish!