Heat the sun-dried tomato oil in a large Dutch oven over medium heat. Add the onion and garlic and cook, stirring often, until softened, about 3 to 4 minutes. Stir in the tomato paste and sun-dried tomatoes and cook for about 2 minutes until the paste deepens in color.
Pour in the chicken broth, heavy cream, basil, salt, Italian seasoning, garlic powder, and crushed red pepper. Bring the soup to a gentle boil. Add the pasta, reduce the heat to medium-low, and cook until the pasta is al dente, stirring occasionally.
Lower the heat and stir in the spinach, shredded chicken, cream cheese, and Parmesan. Cook, stirring often, until the cheeses melt and the soup becomes creamy and smooth. Taste and adjust seasoning, then serve hot with optional garnishes.