Bring a large pot of water to a boil. Add 2 tablespoons of salt and cook the spaghetti as per the package directions.
In a small saucepan, heat 1/4 cup of olive oil over low heat for 1 minute. Add garlic and red pepper flakes. Stir and cook for another minute. Remove from heat.
Drain the cooked spaghetti and transfer to a large bowl. Pour the olive oil mixture and an additional 2 tablespoons of olive oil over the spaghetti. Add lemon juice and parsley. Toss until the pasta is evenly coated.