If you're unable to get your hands on a madeleines pan, then you can, at a pinch, use a cupcake pan. Ensure you go through the same process of preparing the pan by greasing each mould well, dusting them with flour and refrigerating. I have never tried baking them in a cupcake tin, so I cannot guarantee the signature hump, but if the lack of Madeleines' pan stops you from trying these out, I say GO for it. The taste will be identical! Let me know how you go if you do.