Delicate Shell-Shaped Butter Sponge Cakes

Melt the unsalted butter gently and set aside to cool slightly. Preheat your oven to 200°C (400°F).

In a large bowl, whisk together the eggs, granulated sugar, vanilla extract, and lemon zest until light and frothy.

In a separate bowl, sift together the all-purpose flour, baking powder, and a pinch of salt.

Gradually fold the dry ingredients into the egg mixture until just combined, being careful not to overmix.

Slowly drizzle in the cooled melted butter, folding it in until fully incorporated and the batter is smooth.

Cover the bowl and chill the batter in the refrigerator for at least 1 hour, or preferably 2-3 hours. This step is crucial for the madeleines' signature hump.

Generously grease and flour your Madeleine pan. Spoon about 1 tablespoon of the chilled batter into each shell mold, filling it about two-thirds full.

Bake for 10-12 minutes, or until the edges are golden brown and the madeleines have developed their characteristic hump. Remove from the oven, let cool in the pan for a minute, then gently unmold onto a wire rack to cool completely. Dust with powdered sugar if desired.