Place the butter in a saucepan over a medium heat and let it melt. Get a bowl ready and stand it on a heatproof service (a trivet or towel), you will pour the butter into this bowl to stop it cooking further.
Cook the butter until it turns golden. It will bubble up, so you need a spatula or spoon to scrape the bubbles back so you can see the colour. The butter will also start to smell nutty.
As soon as the butter starts to colour pour it straight into the bowl to stop it cooking. Allow to cool completely.
Sift the sugar, almonds, flour and salt into a bowl, add the clementine zest and stir to combine.
Whisk in the egg whites until combined. Finally add the cooled beurre noisette and whisk until it is fully mixed in.
The mixture can then be placed in the fridge overnight or for at least 2 hours. This helps the mixture thicken for baking and to help create the hump on the madeleine.
Just before baking pre-heat the oven to 170 degrees (325 degrees F), Gas 3.
Take the madeleine pan and rub butter into the scalloped moulds, then dust the tray with flour. Tap off the excess flour and then fill each mould with a heaped teaspoon of batter, until it is at least 2/3rds full.
You may find you have batter left over, do not over fill the moulds, you can use this batter to make more madeleines after your first batch.
Bake the madeleines in the pre-heated oven for 12-15mins, you may need to rotate the pan half-way through baking to ensure they cook evenly.
Allow to cool slightly and then remove the madeleines from the pan and place them on a cake rack to cool.
Take the dark chocolate and place it in a small microwaveable bowl and heat in batches, stirring in between. Don't let it get too hot, or expect it all to melt, just give it a stir when it is mostly melted and allow the rest of the chocolate to melt. This is a quick method of tempering and should stop your chocolate going white when dried.
Take the candied peel and chop it into very fine dice. Take a madeleine and dip it in the chocolate at an angle so you get a diagonal line on the madeleines. Allow the excess to drip off.
Take the candied peel and decorate the madeleines with it however you like. Leave to set somewhere (not the fridge) and then store in a tupperware container. Eat within 24 hours ideally.