Make the Cake Batter

1. Melt the butter in a microwave for 45 – 60 seconds or until melted.  Let it cool completely before using.
2. Dissolve the coffee granules and set it aside to cool.
3. In a medium mixing bowl, beat the eggs, caster sugar and light brown sugar using a handheld mixer at medium speed until pale and almost double in volume.  It takes around 6 – 8 minutes.
4. Add vanilla extract and cooled coffee liquid, give it a quick mix.
5. Place a sieve on top of the mixing bowl, sift in the flour, baking powder and salt.  Gently mix until well combined.
6. With the mixer running, slowly pour in the cooled melted butter into the mixture and continue to beat until well incorporated.
7. Switch to a spatula to scrape down the sides and bottom of the bowl to make sure everything is well mixed.
8. Cover the bowl with cling film and refrigerate for 24 hours.

Bake the Madeleines

1. When you are ready to bake the madeleines, preheat the oven to 200℃ fan.
2. Grease the madeleine pan with melted butter, even though your pan is a non-stick one.  If you are not using a non-stick pan, grease the pan with butter and dust the wells lightly with flour.
3. Remove the batter from the fridge. Using a spatula, mix to loosen the batter.
4. Transfer the batter into a piping bag and cut a 25 mm hole of a piping bag.  Pipe the batter into the moulds around 80% full. You can also alternatively spoon the batter into the moulds.
5. Place the filled madeleine pan into the preheated oven and bake for 8 minutes, or until the madeleines are puffed up and the edges are golden.
6.  While they’re still warm, or as soon as you can handle the heat, gently remove the madeleines from the pan and gently transfer them to a wire rack to cool completely.

Make the Glaze 

1. Mix the salt with the icing sugar.  Set it aside.
2. Dissolve the coffee granules in boiling water and set it aside to cool slightly before mixing it with the icing sugar mixture.
3. Mix the coffee liquid with the icing sugar mixture, little by little, mixing in between, until you reach the right consistency.  Since I am looking for a dipping consistency, I used up all the coffee liquid.
4. The glaze should be thin,  glossy, and almost levels itself immediately with the rest of the glaze.

Decorate the Madeleines

1. Make sure the madeleines are completely cool before decorating.
2. Place a sheet of parchment paper underneath to catch any dripping glaze for easy cleanup.
3. Transfer the glaze into a wide mouth jug for easy dipping.  Dip each madeleine.  While the glaze is still wet, sprinkle finely ground walnuts on top for extra crunch.
4. Let the glaze set at room temperature—it will set within about 30 minutes on the countertop.
5. Serve with a cup of tea or coffee. Warning: one is never enough.