With the rack positioned at the highest level, preheat the oven to 400ºF.
Combine the flour, baking soda, and salt and set aside.
With the mixer on low speed, combine the butter with both sugars, the egg yolk, vanilla, and water. (The small quantity of water makes a puffier cookie). Increase the speed to high and beat until thoroughly mixed and light.
With a spoon or dinner fork, combine the creamed mixture with the dry ingredients. (The batter appears crumbly, but as you combine the remaining ingredients, it will come together and clean the bowl.) Stir or hand kneed in the chocolate chips.
Using a heaping tablespoon of batter as a guide, make 13 evenly sized balls and place 2 inches apart onto a cookie sheet. Alternatively, using the tip of another poon, push the batter by heapin tablespoonfuls onto a cookie sheet in well-spaced rounded mounds.
Decrease the oven temperature to 350ºF. Bake the cookies for 5 minutes, then reverse the pan so the back is in the front. Increase the oven temperature to 375ºF. and bake for 4 to 5 minutes longer. The cookies appear golden brown with small pale centers. Cookies will complete cooking as they cool on the pan. The shorter baking time produces a chewier cookie.
Cool cookies in a pan on a wire rack for 2 minutes. Remove the cookies to a wire rack for complete cooling.