So, this is clearly shameless self-promotion, but this is the best lemon cookie recipe I've ever made.
You don't need to make it a sandwich cookie, but it's super fun when you do.
And here's a list of all the lemon cookies that I've tried. I really liked the lemon drop cookies. And they have the added advantage of being super easy.
Thanks everyone for the suggestions. In the end, for this particular occasion I decided to go with a lemon cake, rather than cakey lemon cookies. Unfortunately this was also my first foray into high altitude baking (another topic that I'm sure has been discussed multiple times on this board), and the usual high altitude fixes didn't seem to work, so I ended up with a bit of a sunken mess. Fortunately, the cake still tasted good, and cream cheese frosting hides a multitude of aesthetic sins.