Fill a large pot with water, add a pinch of salt, and bring to a rolling boil. Add the spaghetti and cook until al dente, about 8-10 minutes, reserving 1 cup of pasta water before draining.

In a skillet over medium heat, add olive oil and heat for 1 minute. Add minced garlic and sauté for 1-2 minutes until fragrant and lightly golden.

Transfer drained pasta to the skillet and toss in the garlic oil. Gradually add reserved pasta water until a glossy sauce forms.

Stir in red pepper flakes, salt, pepper, and chopped parsley. Serve immediately, garnished with Parmesan cheese if desired.