In a large bowl, cream together the Butter with both Sugars until light and creamy, about 3 - 5 minutes.
Add the in the Vanilla, Salt and Flour, continue to mix until well incorporated.
The dough will be crumbly, so add in the Milk. Start with 2 Tbls first, blend then if needed add up to 2 additional Tbls of Milk and blend until a stiff but soft dough forms.
Fold in the Chocolate Chips until well combined.
Keep in the refrigerator until ready to serve (or nibble on every time the fridge door is open) for up to a week.