My cousin Angie gave me her old madeleine pan a few years ago when she was spring cleaning (thanks Angie!!!), and since then I've used it quite often. The batter is pretty easy to whip up on short notice, and they only take 10-12 minutes to bake! The only tedious part is having to wipe clean and re-butter/flour the pan for the second batch (since my pan only holds a dozen, and the recipe makes two dozen!).
I use a recipe from my Barefoot Contessa cookbook for coconut madeleines, but I just omit the coconut (although one of these days I'll have to try it with the coconut). The batter can get thick, so I use a mini-ice cream scoop to fill the shells.
The madeleines end up tasting like mini buttery pound cakes - perfect with your morning coffee, or as an afternoon snack with tea!