If serving this sauce with pasta, cook the pasta according to the package directions in a large pot of boiling water until al dente. Drain and set aside.
While the pasta cooks, add the roasted red peppers, heavy cream, crushed tomatoes, basil, and Parmesan to a food processor and blend until smooth. Set aside.
In a large skillet, heat the olive oil over medium heat. Once hot, add in the onion and garlic and cook for 2-3 minutes until softened. Add the Italian seasoning and red pepper flakes and cook another 30 seconds before pouring in the blended red pepper sauce.
Bring the sauce to a gentle simmer for 5 minutes until slightly thickened. Season to taste with salt and pepper.
Then stir in the cooked pasta. Cook until reheated, about 2-3 minutes. Top with shaved parmesan cheese and fresh basil for garnish, if desired.