Preheat your oven to 350 degrees. Make sure that you have at least one rack set up in the lower third of the oven for your cookies.
Stir together your flour and baking soda in a small mixing bowl.
In a larger bowl or mixer, cream the butter until smooth for about 2 minutes. Add your white and brown sugars, as well as your salt. Continue to cream the mixture on a medium speed until smooth. Scrape down the sides of your bowl.
On a lower speed, mix in your egg and vanilla in a 15- 20 second interval. Do not overmix.
On the same low speed as above, incorporate your flour mixture. Your dough will be heavy and dense when smooth, tougher than a bread dough. Fold in chocolate chips.
Prepare your cookie sheet with parchment paper, and drop heaped teaspoons of dough about 2" apart from one another; these cookies are small and bake beautifully at this size. Bake each sheet for 12 - 13 minutes or until light gold on the bottom. Cool at room temperature before storing.