Heat oven to 325 degrees. In a medium bowl, combine 1 1/2 cups flour and confectioners' sugar. Using a pastry cutter, cut in butter until mixture resembles coarse meal. Gently pat into a 9-by-13-inch glass baking dish, and bake until crust is golden brown, 20 to 25 minutes. Transfer dish to a rack to cool.
Reduce oven to 300 degrees. Whisk together eggs and granulated sugar in a medium bowl. Add lemon zest and juice, and combine. Sift in remaining 1/2 cup flour, add nuts, and stir to combine. Pour filling onto baked crust, and bake until filling sets, about 40 minutes. Refrigerate until well chilled before slicing, 1 hour and preferably overnight. Dust with confectioners' sugar, slice into pieces with a sharp knife, and serve.
If you're fond of limes, use fresh lime juice and zest instead.
This is the best lemon square recipe I have tried. The gooey treats consistently knock the socks off of people who try them. The filling is outstanding and plentiful.
I used the recipe and it was a bit sweet (I also used Meyer lemons) but I have a sweet tooth so I loved them.
I reduced the sugar to 2 1/2 cups and thought the flavor perfect. But the almonds on top seemed out of place and made the cookies even more difficult to cut into neat squares. They were terribly messy to cut, and still are impossible to eat without a lot of finger-licking, so I am not sure I want to serve them on my platter of Christmas cookies. I won't make them again.