2 cups (284 g) all-purpose flour
½ teaspoon baking soda
¾ teaspoon salt
½ pound (2 sticks; 227 g) unsalted butter, room temperature
1½ cups (297 g) granulated sugar
¼ cup (50 g) packed brown sugar
1 large egg
1½ teaspoons pure vanilla extract
2 tablespoons water
6 ounces (170 g) bittersweet chocolate, chopped into bite-size pieces averaging ½ inch with some smaller and some larger
Adjust an oven rack to the middle position. Preheat the oven to 350°F. Line 3 Baking Sheets with aluminum foil, dull side up. (I used parchment paper, because I was desperate to make these and was out of foil. I found the results were excellent, but I would suggest doing it on foil, as Sarah suggests.) This helps create the crinkles in the cookies.
In a small bowl, whisk the flour, baking soda, and salt.
In the bowl of a stand mixer fitted with a Beater Blade, beat the butter on medium until creamy. Add the granulated and brown sugars and beat on medium until light and fluffy, 2 to 3 minutes. Add the egg, vanilla, and water and mix on low to combine. Add the flour mixture and mix on low until combined. Add the chocolate and mix on low into the batter.
Scoop the dough into 3½-ounce (100g) balls (a heaping ⅓ cup each). Place 4 balls an equal distance apart on a prepared pan and transfer to the freezer for 15 minutes before baking. After you put the first baking sheet in the oven, put the second one in the freezer.
This step is essential for getting the crinkles on the edge.
Place the chilled baking sheet in the oven and bake 10 minutes, until the cookies are puffed slightly in the center. Lift the side of the baking sheet up about 4 inches and gently let it drop down against the oven rack, so the edges of the cookies set and the inside falls back down (this will feel wrong, but trust me). After the cookies puff up again in 2 minutes, repeat lifting and dropping the pan. Repeat a few more times to create ridges around the edge of the cookie. Bake 16 to 18 minutes total, until the cookies have spread out and the edges are golden brown but the centers are much lighter and not fully cooked.
Transfer the baking sheet to a wire rack; let cool completely before removing the cookies from the pan.