Preheat the oven to 375°F (190°C). Lightly grease the madeleine pan with butter. Dust lightly with flour. This helps the cakes release easily after baking.

In a mixing bowl, whisk eggs and sugar together. Mix until the mixture becomes pale and slightly thick. This step helps create the soft and airy texture.

Add vanilla extract and lemon zest to the egg mixture. Stir gently until combined. These ingredients give the madeleines a fresh and delicious aroma.

In another bowl, combine flour, baking powder and salt. Whisk gently to mix evenly. This step ensures the batter stays smooth and lump-free.

Slowly add the dry ingredients into the egg mixture. Stir gently using a spatula. Mix until just combined. Do not overmix the batter.

Pour the melted butter into the batter slowly. Fold gently until the mixture becomes smooth and silky. The butter adds richness and moisture.

Spoon the batter into each shell mold. Fill about three-quarters full. This allows space for the cakes to rise while baking.

Place the pan in the oven and bake for about 10–12 minutes. The edges should turn golden brown and the centers should feel soft.

Remove the madeleines from the pan immediately. Place them on a cooling rack. Dust lightly with powdered sugar before serving.