Bring a large pot of salted water to a boil. Cook pasta according to package directions. Reserve 1 cup of pasta water and then drain.
In a saucepan, heat olive oil over medium heat. Add garlic and tomato paste, cook for 4-5 minutes until tomato paste darkens in color.
Add heavy cream, simmer for 2-3 minutes.
Add red pepper flakes, dried basil, salt, and pepper. Mix well.
Add grated parmesan, butter, and ½ cup pasta water. Mix until smooth and creamy.
Add cooked pasta and toss to coat evenly. Top with more parmesan, parsley, and chili flakes if desired.