Cook the pasta in salted water according to package directions until al dente. Drain and set aside.
In a large skillet over medium heat, melt the butter and sauté the garlic for about 30 seconds.
Add the cream cheese and stir until it begins to melt and combine with the garlic.
Slowly whisk in the milk to form a creamy sauce, then add parmesan and stir until melted.
Season with salt, pepper, and red pepper flakes if using.
Add the cooked pasta to the sauce and toss until evenly coated.
Serve immediately with a sprinkle of fresh parsley.