01 - Bring a large pot of salted water to a boil. Cook the pasta according to package directions until al dente. Reserve ½ cup of pasta water, then drain the pasta.
02 - Heat butter and olive oil in a large skillet over medium heat. Add the minced garlic and sauté for 1 to 2 minutes until fragrant but not browned.
03 - Lower heat to medium-low and gradually pour in the heavy cream, stirring constantly. Simmer gently for 2 to 3 minutes until slightly thickened.
04 - Stir in Parmesan cheese, salt, black pepper, and red pepper flakes if using. Continue cooking for 1 to 2 minutes until cheese melts and sauce becomes smooth.
05 - Add the drained pasta to the skillet and toss to coat evenly. Adjust sauce consistency by adding reserved pasta water gradually as needed.
06 - Remove from heat and fold in the chopped parsley.
07 - Plate immediately, garnishing with extra Parmesan and a sprinkle of parsley.