Preheat oven to 350 degrees. Spray 9 x 13 baking dish with cooking spray, set aside.
Place chopped chicken in a large mixing bowl and set aside. Squeeze liquid from the spinach and drain the can of artichoikes. Add to bowl with chicken. Stir to combine.
In a small mixing bowl, stir together cream cheese, sour cream, and ranch dressing. If needed pop the cream cheese into the microwave to soften it. It makes it easier to mix together.
Add the cream cheese mixture, bacon and 1 cup of mozzarella cheese to the chicken. Stir until fully combined.
Pour chicken mixture into prepared 9 x 13 casserole dish. Top with remaining mozzarella cheese and cover with foil.
Bake for 25-30 minutes, remove foil, and bake an additional 10 minutes or until bubbly and cheese is melted.