Sent by Allison Editor: That looks divine, Allison. We don't quite know where to start either, although hopefully one of the readers will recognize this sort of tart!
We do think playing around with a clafoutis recipe might give you some interesting results. Also, the other thing we immediately thought of was lemon pudding cake. What about trying that recipe and baking it in a tart mold?
Good luck, and please let us know if you identify the correct recipe; it sounds like something we'd love to try.
Related: Recipe: Gâteau de Zoë