Cook the Pasta:Bring a large pot of salted water to a boil. Cook the pasta according to package instructions until al dente. Reserve 1/2 cup of pasta water before draining.
Make it Creamy:Lower the heat and stir in the heavy cream. Let it simmer gently for 2-3 minutes. Add the Parmesan cheese, salt, and pepper, stirring until the cheese is melted and the sauce is smooth.
Combine:Toss the cooked pasta into the skillet with the sauce. Add a splash of reserved pasta water if the sauce needs to be thinned. Stir until the pasta is well-coated.
Serve:Garnish with fresh parsley and a sprinkle of red pepper flakes, if desired. Serve hot.