01 - Bring a large pot of salted water to a boil and cook pasta until al dente according to package directions. Reserve ½ cup pasta water and drain.
02 - Heat butter and olive oil in a large skillet over medium heat. Add minced garlic and sauté for 1 to 2 minutes until fragrant without browning.
03 - Reduce heat to medium-low, pour in heavy cream, stirring constantly. Let simmer gently for 2 to 3 minutes until slightly thickened.
04 - Stir in Parmesan, salt, black pepper, and optional red pepper flakes. Cook for 1 to 2 minutes until cheese melts and sauce becomes smooth.
05 - Add drained pasta to skillet and toss to coat thoroughly. Add reserved pasta water gradually to achieve desired sauce consistency.
06 - Remove from heat and fold in chopped parsley evenly throughout the pasta.
07 - Dish immediately, garnished with extra Parmesan cheese and a sprinkle of parsley.