Bring a large pot of salted water to a boil and cook the pasta until al dente according to the package directions.
Before draining, reserve ¼ cup of the pasta cooking water.
Drain the pasta and set it aside.
In a large skillet, melt the butter over medium-low heat.
Add the minced garlic and cook for 1–2 minutes until fragrant, stirring constantly.
Stir in the Italian seasoning, onion powder, black pepper, and red pepper flakes if using.
Add the cooked pasta to the skillet.
Pour in the reserved pasta water and toss until the noodles are evenly coated with the buttery garlic sauce.
Stir in the chopped parsley.
Sprinkle with Parmesan cheese if desired and serve immediately.