Heat 1 tablespoon of sun-dried tomato oil in a large Dutch oven over medium heat.
Add onions and garlic, cooking for 3-4 minutes until softened and fragrant.
Stir in tomato paste and sun-dried tomatoes; cook for 2 minutes, stirring constantly.
Pour in chicken broth, heavy cream, basil, salt, Italian seasoning, garlic powder, and crushed red pepper.
Bring to a gentle boil over medium heat, stirring occasionally, then simmer for 12 minutes.
Add pasta, reduce heat to medium-low, and cook for 12 minutes until pasta is tender.
Lower heat to low; stir in spinach, shredded chicken, cream cheese, and Parmesan.
Stir often for 5 minutes until cheeses melt and chicken is warmed through.
Ladle into bowls; garnish with extra Parmesan, fresh basil, and red pepper flakes.
Serve immediately with crusty bread or a fresh green salad.