In a large pot, bring salted water to a boil. Cook the spaghetti until al dente, following the package instructions. Drain the pasta and set it aside.

In a large skillet over low heat, combine the olive oil, garlic, parsley, and crushed red pepper flakes. Sauté for about 3-5 minutes until the garlic becomes golden and fragrant. Keep an eye on it to avoid burning the garlic.

Add the drained pasta to the skillet with the garlic mixture. Toss to coat the spaghetti in the flavorful oil and garlic. Stir in the melted butter until everything is well combined.

Top with grated Parmesan cheese and season with salt and pepper to taste. Serve immediately.