Preheat the oven to 325°F/170°C/Gas 3. Line two baking sheets with nonstick baking mats or parchment paper. Set them aside.

Whisk or sift the flour, baking soda, and salt together in a bowl. Set it aside.

Using a paddle attachment on an electric mixer, mix the brown sugar, white sugar, and cooled melted butter for one minute.

Continue beating the mixture for one minute while adding the egg, egg yolk, and vanilla extract. Use a rubber spatula to scrape down the sides of the bowl.

On a low speed, mix in the flour mixture until just combined.

Fold the cranberries, pecans, walnuts, and white chocolate chips into the dough using a spatula.

Use an ice cream scoop to form dough balls and place them onto the prepared baking sheets about 2"/5cm apart.

Place in the preheated oven for 15 minutes, turning the pan halfway through baking time.

Remove the cookies from the oven and press extra nuts and chocolate chips into the warm cookies.

Leave the cookies to cool on the baking sheet for 10 minutes before transferring them to a wire rack to cool completely.