Bring a large pot of water to a boil. Add the spaghetti and cook al dente, two to three minutes before the time indicated on the package.
In a large skillet, heat olive oil, minced garlic and red pepper flakes over medium-low and cook until garlic is lightly golden. Reduce heat and add 2 ladles of pasta water.
Add al dente spaghetti to the skillet and toss with sauce. If dry, add pasta water to create a silky sauce.
Remove from heat. Sprinkle with chopped parsley and mix well.