Bring a large pot of salted water to a boil.
Cook the spaghetti according to package directions until al dente.
Reserve 1/4 cup of pasta water before draining.
Melt the butter in a large skillet over medium heat.
Add the garlic and cook for 1 minute until fragrant.
Stir in the Italian seasoning, salt, and black pepper.
Add the drained pasta to the skillet.
Toss until the pasta is coated in the garlic butter.
Add the Parmesan cheese gradually while tossing.
Pour in the reserved pasta water and mix until creamy.
Sprinkle with parsley.
Serve immediately with extra Parmesan if desired.