Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions until al dente. Reserve 1/2 cup of pasta water, then drain the pasta in a colander.

While the pasta cooks, melt butter in a large skillet over medium heat. Add the heavy cream and stir to combine. Let it gently simmer for 2-3 minutes, stirring occasionally.

Add the grated Parmesan cheese to the skillet. Stir continuously until the cheese melts and the sauce is smooth, about 2 minutes. Season with salt and pepper.

Add the drained pasta directly into the skillet with the Alfredo sauce. Toss until the pasta is evenly coated. If the sauce is too thick, add reserved pasta water, a little at a time, until desired consistency is reached.

Taste and adjust seasoning if needed. Serve immediately, garnished with chopped parsley if desired.

For extra richness, consider adding a splash more cream or incorporating grilled chicken, shrimp, or steamed broccoli for variation.