Beranbaum says that she developed this recipe to address two problems that lemon bars are prone to: A topping that is not firm enough, and a base that is too soggy.
These bars address those two issues by first of all making a true Scotch shortbread, with tons of butter. You pat it into the pan, prick it all over, and bake it sans lemon topping. This helps the base to firm up and get that flaky, crumbly texture essential in good shortbread.
Then, for the topping, instead of just mixing lemon and eggs together and pouring the mix over the base, you take the time to create a true lemon curd. You whisk and stir the eggs, butter, and lemon juice until it cooks (but not curdles!) and firms up into a thick, creamy lemon curd.
After that you spread the curd on the shortbread base and bake it for just a few minutes to let it set, but the two components of the bars are mainly cooked separately. This definitely takes some extra work, and some fiddling with candy thermometers and such, but boy. The end results are so worth it. These bars are extra-flaky on the bottom, with a firm, buttery bite, and the top is thick and creamy and bursting with lemon flavor. They are incredibly tangy and delicious — like a bite of sunshine.
I can definitely recommend this recipe wholeheartedly; even though there are easier recipes for lemon bars, this is the one I return to over and over. It gets an extra thumbs-up for Beranbaum's detailed and reliable instructions, too; she is such a wonderful writer and recipe developer, and her recipes always go the extra mile in providing tips and instructions.
(Images: Faith Durand)