Makes about 24
130 grams unsalted butter
3 eggs, at room temperature
1 egg yolk
120 grams granulated sugar
pinch of sea salt
175 grams flour, plus extra for dusting
1 teaspoon baking powder
zest of 2 medium oranges for the glaze (optional)
150 grams confectioner's sugar
2 tablespoons freshly squeezed orange juice
Melt the butter in a small saucepan on medium heat until it just starts to turn golden brown. Be careful not to overheat. Set aside to cool.
Using a pastry brush, generously grease the madeleine tin with a little of the melted butter. Dust with flour and place the tins in the refrigerator to set.
Using a stand mixer, whisk the eggs, egg yolk, sugar and the salt until the batter starts to thicken, about 5 minutes.
Sift the flour and baking powder and use a spatula to fold the flour into the batter mixture.
Add the orange zest to the cooled butter, then slowly drizzle the butter into the batter until you have incorporated all of the butter in the mixture.
Cover the bowl and place in the refrigerator for at least 1 1/2 hours. Preheat the oven to 425 degrees F.
Drop the batter in the middle of each mold until about three-quarters full without spreading it. Bake for 8 to 9 minutes in the upper third of your oven. Bake until slightly brown or just until they feel set to the touch.
To make the glaze, stir together the confectioner's sugar and the orange juice.
Remove the madeleines from the oven and place on a cooling rack. When cool, using a pastry brush, apply the glaze on both sides. Leave on the rack until the glaze has set. Or, as another option, you can simply dust with confectioner's sugar.