1. Preheat the oven to 195 degrees, or 175 degrees if using a fan. Line two baking trays with parchment paper.

2. Place the hazelnuts on a separate tray or small dish and place in the oven for about 10 minutes, until lightly toasted. Leave to cool slightly, then place on a chopping board and finely chop. Set aside.

3. Roughly chop the chocolate into small chunks and set aside.

4. Cream together the butter and soft brown sugar in a large bowl by hand, using an electric whisk or in a stand mixer, until pale and soft.

5. Add the condensed milk and continue to beat together until the mixture is smooth.

6. Sift in the dry ingredients (the flour, salt, and baking powder), and add the cooled chopped hazelnuts and chopped chocolate chunks.

7. Mix everything together to form a lumpy cookie dough; the chocolate and hazelnuts should be evenly dispersed throughout the dough.

8. Divide the dough into about 16 and roll into walnut-sized balls. If you want to be precise, the balls should weigh about 45g each.

9. Place on the baking trays, leaving a few centimetres between each. If you are short on oven space or don’t have enough trays as needed, you can cook the cookies in batches.

10. Bake the cookies for about 12-15 minutes. Remove from the oven and tap the trays on the work surface to help flatten them and give them their signature crackle.

11. If the cookies aren’t a perfect circle once baked, use a large cookie or scone cutter (slightly bigger than your cookies) to help shape the cookies into circles. Swirl each cookie in the cutter until they become perfectly round.

12. Leave the cookies to cool, they will continue to cook a little on the tray.

13. Once cool, the baked cookies can be drizzled with melted chocolate or sprinkled with a little sea salt for added flavour. They will keep for a few days in an airtight container.