In a large pot, bring salted water to a rolling boil. Add the spaghetti and cook according to package instructions until al dente. Reserve about 1 cup of pasta water, then drain the spaghetti.

In a large skillet, melt the butter over medium heat. Allow it to bubble gently; it will release a nutty aroma.

Add the minced garlic to the skillet and sauté for about 1-2 minutes, until it turns golden brown. Be careful not to burn it.

Add the drained spaghetti into the skillet with the garlic butter. Toss well to coat the pasta in the fragrant butter.

Sprinkle in the grated Parmesan cheese and pour in a little reserved pasta water to help create a creamy sauce. Toss again, adjusting the consistency with more pasta water if needed.

Adjust the flavor with salt, black pepper, and red pepper flakes, if using. Remember to taste as you go.

Serve immediately, garnishing with freshly chopped parsley and additional Parmesan if desired.