Preheat the oven to 350°F. Lightly spray the bottom and sides of a deep 13x9-inch baking dish with cooking spray.
In a medium-size mixing bowl use an electric mixer to whip together the ricotta, cream cheese, Ranch dressing and sour cream until fluffy and combined
By hand mix in the spinach, artichoke hearts, green onion, 1/3 cup Parmesan, Italian seasoning, garlic salt, garlic powder, red pepper flakes and black pepper. Mix until the ingredients are evenly distributed.
To assemble drizzle the bottom of the dish with with 2/3 cup Alfredo sauce and arrange 5 noodles over the sauce.
Spread the noodles with 1/2 of the spinach filling, top with 1/2 chopped chicken and 1 cup shredded cheese. Repeat ending with a final layer of noodles.
Drizzle the remaining Alfredo sauce on top and spread to cover.the noodles. Cover with foil and bake for 55 minutes or until the noodles are fork tender.
Remove the foil and sprinkle with the remaining 1 cup shredded cheese and 2 Tbsp grated Parmesan. Bake uncovered for 10-15 minutes longer until golden and bubbly. Broil at the end to brown further, if desired.
Let stand for 10 minutes, then cut and serve. Garnish with chopped Italian parsley.