Madeleines

Beating eggs and sugar until very light incorporates air bubbles that act as leavening, while the proteins in the eggs provide structure. The folding technique preserves these delicate air bubbles rather than deflating them through vigorous mixing. Melted butter added at the end coats flour proteins, limiting gluten development and ensuring the characteristic tender, cake-like crumb. The high oven temperature (425°F) sets the structure quickly, creating the signature hump and shell-like shape before the batter can spread.