I picked out a recipe called Luscious Lemon Squares for Linus and I to try baking together. Luscious means 'a pleasingly rich, sweet taste' and I think that nails the sensation of these little joys.
The pastry/base is incredibly delicate, rich and buttery, and the explosion of the lemon curd-like filling is wowing. Its pretty straightforward and simple to make too (not too many steps). Definitely a keeper.
I used the Betty Crocker recipe called Luscious lemon squares that I found online (I reduced the sugar content of the filling from 1 cup to 3/4 cup but that seemed to reduce the volume needed to spread across the entire base).