Cook the pasta. Bring a large pot of salted water to a boil and cook the penne according to package directions until al dente. Before draining, reserve ⅓ cup of pasta water. Drain and set aside.
Meanwhile start the creamy sauce. While the pasta cooks, heat the olive oil in a large skillet over medium heat. Add the garlic and chili flakes and sauté for about 30 seconds, just until fragrant.
Stir in the canned tomatoes, salt, pepper, and dried basil. Bring to a gentle simmer and cook for 5–7 minutes, stirring occasionally, to let the flavors come together.
Reduce the heat to low. Stir in the cream cheese until completely melted, then add the heavy cream and Parmesan. Stir until the sauce is smooth and creamy.
Stir in the sun-dried tomatoes and fresh spinach. Cook for 1-2 minutes, just until the spinach has wilted.
Toss with the pasta. Add the cooked penne directly to the skillet and toss until well coated. Add the reserved pasta water a little at a time as needed until the sauce is silky and coats the pasta nicely.
Finish and serve. Taste and adjust the salt and pepper as needed. Serve warm topped with fresh basil and extra Parmesan.