Cook pasta according to package directions; rinse and set aside.
Heat olive oil in a large skillet over medium-high heat. Add onion and saute for 3-5 minutes, or until onion is tender. Add garlic and cook for an additional minute.
Mix in tomato paste, diced tomatoes, oregano, basil, salt and pepper until well combined. Reduce heat to low and mix in cream cheese and parmesan and stir until incorporated.
Fold in cooked pasta, chicken and spinach and stir until spinach is wilted and pasta and chicken are heated through. Remove from heat and serve.