Bring a large pot of salted water to a rolling boil. Add the egg noodles and cook according to package directions until al dente. Before draining, reserve about 1 cup of the starchy pasta water. Drain the noodles well.

While the noodles are cooking, melt the butter in a large skillet over medium heat. Add the minced garlic and sauté for about 1-2 minutes until fragrant, being careful not to burn it. If using, add the red pepper flakes.

Pour in the heavy cream and bring to a gentle simmer. Stir in the grated Parmesan cheese until it melts into the cream, creating a smooth sauce. Season with salt and black pepper to taste.

Add the drained egg noodles directly to the skillet with the sauce. Toss gently to coat the noodles evenly. If the sauce seems too thick, add a splash of the reserved pasta water, a tablespoon at a time, until you reach your desired consistency. The starch in the water will help emulsify the sauce.

Stir in the chopped fresh parsley. Toss once more to combine. Serve immediately.