Instructions

1. In the bowl of a food processor, combine flour, light brown sugar, granulated sugar, salt, cornstarch, and baking soda.
2. Process until well-combined.
3. Add cold butter and pulse to form a dry and powdery mix.
4. In a separate bowl, whisk together the egg, water, and vanilla.
5. Add the egg mixture to the food processor.
6. Pulse until the dough just begins to come together. It will still be somewhat crumbly at this stage.
7. Turn out the dough onto a work surface.
8. Knead the chocolate chips into the dough by hand until they are evenly distributed and the dough comes together fully.
9. Divide the dough into about 30 portions with a 1-tablespoon scoop.
10. Arrange the portions on a parchment-lined half-sheet pan, leaving about 2 or 3 inches between cookies to account for spread.
11. Bake at 350°F for about 16 minutes, until the cookies are thin and golden brown, with an even color from edge to center.
12. Cool the cookies directly on the baking sheet until they reach room temperature.
13. Transfer the cookies to an airtight container and allow them to cool for an additional hour to fully crisp.