Bring large pot of salted water to boil to cook the pasta. Cook pasta according to directions. Save 1 cup of pasta water before draining pasta.

While pasta cooking, zest the lemons and juice them. You need 1/2 cup of juice. Mince garlic and cut the basil into eibboma.

In a large skillet with sides, heat on medium high and add 4 Tbsp butter and the olive oil. Add in the zest, juice and 1/2 of the basil and the crushed red pepper flakes. Stir to combine. Turn heat down to medium low until pasta is done.

Reserve the cup of pasta water. Drain the pasta and add to skillet tossing with the garlic, lemon and basil. Add the last 2 Tbsp butter and the pasta water. Stir to make sauce. Add in the rest of the basil and Parmesan. Tossing to coat all the pasta. Adjust seasoning with the salt and pepper.