Heat the oven to 350°F (180°C). Line a large baking tray with parchment paper.
Beat the soft butter and sugar in a large bowl until soft and creamy.
Add the flour, salt, vanilla and chocolate chips. Mix to a firm dough.
Turn the dough onto a lightly floured surface and knead gently until smooth. Roll it to 1/2 inch thick.
Cut rounds with a 2 1/2 inch cutter. Re-roll the scraps and cut more.
Place the rounds on the tray, poke the tops with a fork, and chill for 30 minutes.
Bake for 15 to 18 minutes, until lightly golden.
Cool on the tray for 5 minutes, then move to a wire rack to cool completely.