Preheat the oven to 200°C/400°F (180°C fan/Gas 6). Measure out the egg white and set aside.
Brown the butter: melt the chopped butter in a saucepan over a medium heat. Once the butter starts to foam, continue for another 5 minutes or until it starts to turn light golden brown (like its name 'beurre noisette', it should be the colour of hazelnuts). To tell it's ready, the butter will start to 'chirp' like a bird. Take off the heat and set aside.
Mix all the dry ingredients in a bowl. Add the egg whites and mix in the slightly cooled browned butter. Set aside to cool for about 10 minutes in the fridge.
Place the moulds on a baking sheet. Using a spoon, fill silicone moulds and sprinkle with the flaked almonds.
Bake in the oven for 13-15 minutes (or 10 mins if using mini moulds)
