Combine the eggs, sugar and orange zest in a bowl and whisk vigorously for 10 minutes until the mixture is thick, foamy and very pale in colour.
Then add the vanilla extract.
In a separate bowl, combine the flour, baking powder and salt.
Gently fold the dry ingredients into the egg mixture making sure everything is combined.
Then fold in the melted butter into the batter.
Cover and chill in the fridge for at least an hour.
Preheat the oven to 180°C.
Lightly grease your Madeleine pan with butter before scooping a tablespoon of batter into each well.
Bake for 10-12 minutes or until lightly browned.
Allow to cool before serving with grated orange zest and a dusting of icing sugar.
