Dark Chocolate Chunk Cookies

1. Preheat your oven to 180°C / 350°F. Line two baking trays with parchment paper.

2. In a large bowl, beat the softened butter with the brown sugar and white sugar until pale and fluffy — about 2 minutes by hand or 1 minute with electric beaters.

3. Add the egg, egg yolk, and vanilla extract. Beat well until smooth and slightly glossy.

4. Sift in the flour, bicarbonate of soda, and salt. Fold together with a spatula until just combined — don't overwork the dough or the cookies will be tough.

5. Add the dark chocolate chunks and fold through evenly.

6. Scoop the dough into balls roughly the size of a golf ball (about 2 tablespoons each) and place on the prepared trays, leaving at least 5cm between each one as they will spread.

7. For extra-chewy cookies, refrigerate the dough balls for 30 minutes before baking — totally optional but worth it if you have the time.

8. Bake for 11–13 minutes until the edges are set and golden but the centres still look slightly underdone and glossy. They will firm up as they cool.

9. Leave to cool on the tray for at least 10 minutes before eating — this is where the texture sets. Try to resist.

10. Store in an airtight container at room temperature for up to 5 days. They also freeze brilliantly as raw dough balls — just add 2 extra minutes to the bake time from frozen.