Mix all the dry ingredients in a medium size bowl.
In another bowl mix the wet ingredients.
Fold in the wet ingredients and the chocolate chips into the dry ingredients with a wooden spoon until just combined. It will be a stiff dough, if it is too dry add a bit more milk (start with just 1 tbsp). It shouldn't be too wet though!
Place the batter in the refrigerator for about 20-30 minutes to stiffen up.
In the meantime preheat the oven to 325F/ 165C. And line a baking sheet with parchment paper or a nonstick baking mat.
Scoop batter with an ice cream scoop (or you can also use a spoon (1½-2 tbsp)). Space them evenly on the baking mat allowing room for them to spread a little bit. No need to press the cookies down.
Bake the cookies for 9 minutes. They will definitely still look underbaked, but take them out anyway for a fudgy-centered cookie. Leaving them in longer will result into dry cookies.
Let them set on the baking sheet for a few minutes before transferring them to a cooling rack for further cooling. They are best if you eat them straight away. If you do want to store them, it is best to do so in a glass container. I wouldn't recommend storing them for more than a day or two. But who knows? I have never been able to keep cookies that long..