To make browned butter, place the butter in a small pan and heat it over medium heat. The butter should melt, then foam, and finally brown. Leave the butter to cool down slightly.

Add both brown and granulated sugar to a large mixing bowl. Pour the browned butter over the sugar, and using a handheld electric mixer, beat the mixture for 2 minutes until the sugar starts dissolving (it will still be grainy, and it's ok).

Add an egg yolk and whisk again for approx 2 minutes.

Add the sourdough discard and mix with a balloon whisk until combined (you don't want to use an electric mixer here as it will promote gluten development).

In a separate bowl, mix flour, baking soda, nutmeg and salt.

Add the dry ingredients to the wet ingredients and mix just enough to combine.

Cover the dough and place it in the fridge for 4 hours.

Preheat the oven to 180°C (350°F). Line a large baking sheet with parchment paper.

Divide the cookie dough into 6 even pieces (approx 70-72g each) and shape each into a ball.

Bake the cookies for 14-16 minutes. The cookies should have browned crispy edges, but the centre should still be a little soft and puffy. As soon as you take the cookies out of the oven, drop the tray from 20cm height onto a kitchen worktop - this creates that signature cracked tops.

Leave them on the tray for 10 minutes to firm up. Then transfer the cookies onto a cooling rack.