Bring a large pot of water to a boil and cook the pasta according to the package directions. Reserve ½ cup of pasta water before draining the pasta and returning it to the pot. While the pasta cooks, make the sauce.
Make the sauce:
In a small saucepan over medium heat, combine the olive oil, butter, garlic, salt, red pepper flakes, lemon juice, and lemon zest. Cook the mixture for about 2 minutes, stirring frequently, until the garlic is toasted to a golden color and fragrant but not burned. Turn off the heat.
Combine:
Pour the lemon sauce over the pasta and add the fresh chopped basil into the pot. Toss to combine until all the pasta is coated with the lemon basil.
Serve:
Serve the lemon basil pasta sprinkled with parmesan cheese on top.