Melt the butter. Once the butter has cooled down, whisk in the sugars.
Stir in milk (or an egg yolk)
Sift the flour, baking soda and salt into the same bowl. Gently fold to combine. Stir in chocolate chips.
Tip the cookie dough out into a small baking dish and pop it in a preheated oven at 180C for 8-12 minutes until the edges have puffed, turning golden-brown, but the centre is still soft.
Serve hot with ice cream
