In a medium bowl, mix together the flour, salt and baking soda. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, cream the butter with both sugars until light and fluffy. Add the egg, egg yolk and vanilla, and beat well. Mix in 1/3 cup room-temperature water.
Mix in the flour mixture until well-combined then stir in the chocolate chips.
Scoop the dough into balls slightly smaller than a golf ball onto a parchment-lined baking sheet (you’ll need a second sheet for baking). Since the dough is rather wet, use a 1.5-ounce kitchen or ice cream scoop if you have one. The cookies can be placed close together on this sheet because they’re just going to set up in the freezer for a while. Chill the cookies in the freezer for 30 minutes to 1 hour.
Preheat the oven to 325ºF. Line another baking sheet with parchment paper.
Take the cookies off the frozen baking sheet and place them at least 3 inches apart on the new sheet. Let them warm up just enough so you can squish them. Pressing with your palm or the flat bottom of a glass, gently flatten each cookie to about 1/4-inch thick. This is super thin, but there is a huge difference between 1/2-inch and 1/4-inch thick. These would be two VERY different cookies.
Bake for 20-25 minutes, or until kinda dark golden brown. Let cool on the baking sheet on a wire rack for 15 minutes.