Preheat your oven to 375°F (190°C).
In a large mixing bowl, combine the frozen hash browns with half of the shredded cheddar cheese and half of the mozzarella cheese.
In a separate bowl, mix together the cooked, shredded chicken, sour cream, green onions, garlic powder, onion powder, salt, and pepper.
Gently fold the chicken mixture into the hash brown mixture until everything is nicely incorporated.
Pour the mixture into a greased 9x13-inch baking dish, spreading it out evenly.
Sprinkle the remaining cheddar and mozzarella cheese on top, followed by the crumbled turkey bacon.
Place the baking dish in the preheated oven and bake for 30-35 minutes, or until the cheese is melted, bubbly, and slightly golden brown.
Once baked, let the casserole cool for a few minutes before serving.