Pre-heat the oven to 180'C / Fan 160'C / Gas Mark 4. Line two large baking trays with baking paper and set to one side.

Melt the butter in a large pan on a low heat. Once melted, remove from the heat immediately (you don't want it to start bubbling or boiling) and stir in the sugar, eggs and vanilla extract. Stir well until it forms a thick, sticky batter.

In a separate mixing bowl add the flour and salt and stir to mix together. Pour the dry mixture into the butter mixture and stir with a wooden spoon well until fully combined. It will become quite thick as the butter cools so you may need some elbow grease!

Add the chunks of chocolate and stir until they are evenly distributed throughout the mix.

To make the cookies, place around one-and-a-half heaped dessert spoonfuls of dough in blobs at least two inches apart on the baking tray. These will spread so the extra space is important - you may have to bake them in batches of 3-4 per tray depending on the size of your oven.

Smooth the blobs of dough into round shapes using your hands and then bake for 8-10 minutes. You'll know they're done when the cookies have spread out and turned golden brown with a slight crackle on top.

Remove from the oven onto a cooling rack and let them cool on the tray for at least 10-15 minutes before attempting to move them, as they will be soft! While the cookies are still hot, you can also place a few extra chocolate chunks on top of each for decoration.