Preheat oven to 350 degrees F.
Spray 9x13-inch baking dish with nonstick cooking spray; set aside.
Cook pasta according to package directions and drain.
Place spinach on paper towel and squeeze until almost all moisture has been removed.
Add oil to a large nonstick skillet and place over medium heat. Add onion and garlic and sauté until tender.
Add chicken and cook until no longer pink, stirring occasionally.
Stir in tomatoes, marinara sauce, tomato paste, basil, oregano and crushed red pepper flakes. Bring to a boil and then reduce heat.
Simmer 5 minutes, uncovered stirring occasionally.
Combine pasta, spinach, chicken mixture and 1/4 cup cheese in a large mixing bowl.
Spoon into prepared baking dish and sprinkle with remaining 1/4 cup Parmesan cheese over the top.
Bake for 20 minutes and serve.