Preheat oven to 350°F. Line 2 baking sheets with parchment paper.

Beat butter and sugar together until light and fluffy. Add the salt and vanilla extract, beat for 1 more minute.

Add the flour and beat until it comes together as a dough. Add 2tbsp milk and beat until mixed. Dough has to be like thick frosting - if it is too thick, then it will be very difficult to pipe them out. So make sure that the dough is not too thick and not too runny.

Fill a piping bag fitted with a large start tip with the dough. Pipe out circles or 'S' shapes onto the prepared baking pans.

Bake for 12~15 minutes or until the cookies are firm and very lightly golden. Remove onto a wire rack to cool completely.