Madeleine is a classic traditional small cake from Lorraine region in northeastern France. What makes a 'true' madeleine from other versions is recognizable hump. Because the batter is chilled prior to baking. Indeed, approximately 15% of the CO2 gas is released in the cold stage. Eighty-five percent of the CO2 gas is released in the oven. The temperature difference between the oven and the batter creates a burst of steam that results in a hump.
Pro Tips: Do not overwork the egg-sugar mixture. Refrigerate batter for at least 2 hours to relax prior to baking. Use a pizza stone, or an empty baking tray that will be placed in the oven during preheating.
Melt butter with lemon zests. Gently beat eggs with sugar (do not overwork). Incorporate the sifted powders, and warm butter. Madeleine can be pipped out right away and refrigerated but the result wont be the same. It is best to cover and refrigerate batter for 2 minimum. You can skip the pastry bag and use a spoon instead. Butter and grease madeleine sheets. Madeleine cookie should not exceed 30 grams in weight.
Set oven on regular bake sitting. Place oven rack and pizza stone from 8''/20cm from bottom. Place the filled madeleine sheet (one at the time) straight onto the hot pizza stone (no baking tray needed). Bake madeleine at 500ºF/260ºC for 5 minutes. Lower oven temperature to 350ºF/180ºC, and continue baking for about 5 minutes more. Store madeleine in a sealed container, or freezer bags for a few days. Madeleine can also be kept frozen for a few weeks. Enjoy!