1. In a stand mixer fitted with the paddle attachment, or by hand with a wooden spoon or spatula in a bowl, beat the butter and sugars on medium speed until light and creamy, about 5 minutes.
2. Stop the mixer and scrape down the sides with a rubber spatula, reaching down to the bottom of the mixer bowl. Beat in the egg, WATER, and vanilla.
3. In a medium bowl, mix together the flour, salt, and baking soda. Add the chocolate chips, and toss in the flour mixture. With the mixer on low speed, stir in the flour and chocolate chip mixture until thoroughly combined. Cover the bowl (or transfer to a smaller container, and cover) and refrigerate the dough at least 3 to 4 hours, or overnight.
4. To bake the cookies, preheat the oven to 350ºF (180ºC). Line two baking sheet with parchment paper. Arrange the dough, formed in 1 1/4-inch (1/4 cup, 45g) balls on the baking sheet, spaced at least 3-inches (8cm) apart. (They will spread, so expect to get 5 or 6 on a standard baking sheet.) Press the cookies down slightly with your hand and bake until the cookies have spread and just until there are no light patches across the center, rotating the baking sheet(s) midway during baking so they bake evenly. They’ll take about 13-14 minutes, but best to check the cookies a few minutes before and use the visual clues, rather than adhere to strict baking time, to get them just right.
5. Remove the cookies from the oven and let cool for 5 minutes. Transfer the cookies to a wire rack and cool completely.