Cantucci (Biscotti di Prato) vs Classic Madeleines: French Shell-Shaped Cakes

Both bakes start the same way, with eggs whipped with sugar and vanilla until pale and fluffy, but they head in opposite directions. Cantucci contain no butter; orange zest perfumes a dense, sticky dough studded with whole raw almonds, which is baked as logs, sliced and baked again until crisp and crunchy. Madeleines fold in melted butter and lemon zest, rest in the fridge, then bake briefly in shell molds into tender cakes with golden edges and a signature hump that springs back to the touch.