Whisk flour, salt, and baking soda together in a bowl. In a separate bowl, cream the butter, white sugar, and brown sugar together until mixture is light and fluffy, 3 to 4 minutes. Add the egg, milk, and vanilla extract. Whisk liquids together in small areas around the bowl, then all together to avoid separation.
Pour dry ingredients into the wet ingredients; stir until flour is thoroughly mixed in. Stir in the chocolate chips.
Transfer dough to a resealable plastic bag. Refrigerate until dough is firm, at least 2 hours.
Preheat oven to 375 degrees F (190 degrees C). Line baking sheet with parchment paper.
Scoop out rounded tablespoons of dough and place on prepared baking sheet, leaving 4 inches of space between cookies (about 8 per sheet). Bake in preheated oven until cookies are golden brown, about 12 minutes. Slide parchment and cookies onto a cooling rack for a few minutes. Remove parchment and finish cooling the cookies on the rack.