Cream the butter and sugar together in a large freezer-safe bowl, until light and fluffy. You can use either a mixer or simply a wooden spoon to do this and mix the two together until you have a light yellow, fluffy mixture.*
Add the rest of the wet ingredients (the milk and vanilla extract) to the bowl and mix well.
Sieve the flour, baking soda and salt into the bowl.
Fold the wet and dry ingredients together, try not to over-mix.
Carefully fold in the chocolate and chopped/crushed nuts then move the bowl to the freezer for 30 minutes. **
Using an ice-cream scooper, scoop the dough into balls and place on a parchment paper-lined baking sheet. Make sure there's plenty of space between each cookie since they will spread. I was able to fit 6 cookies to a tray.
The cookies are there ready to bake in the oven for 10-12 minutes at 165ºC/350ºF, till golden brown.
Let the cookies cool down on a baking rack.
Store in an airtight container for up to 3 days at room temperature or freeze for up to a month. Make sure to place a baking paper in between individual cookies in the freezer container to avoid them sticking together.
Video
Notes
* Be careful not to over mix this or you'll end up beginning to separate the butter. If using an electric mixer the process only takes between 1-2 minutes, so keep an eye on it.
**Chilling the cookie dough improves your cookies tenfold for a number of reasons;
First, it stops the spreading of the cookies, leading to the delicious ooey-gooey cookies we want (the colder the dough, the thicker the cookies). It also affects the texture from being just 'soft' to deliciously 'chewy'. Moreso, chilling your cookie dough also concentrates the flavour ( because as you're chilling the dough, it slightly dries out and the sugars within are affected too) and adds new layers of flavour as well as helps the cookies brown more.
Note: The Total time does not include 30 mins chilling time.