01 -
Melt the butter in a light-colored saucepan over medium heat. Cook, stirring often, until the foam settles and the milk solids turn golden brown, 4-6 minutes. Scrape into a large bowl and cool for 10 minutes.
02 -
Whisk the water, brown sugar, egg, egg yolk, and vanilla into the cooled browned butter until thick and glossy. The butter should be warm, not hot.
03 -
Add the flour, cornstarch, baking soda, and salt. Stir with a spatula just until the dough comes together and no dry flour remains.
04 -
Cover the bowl and chill for 45 minutes, or until the dough is cool and scoopable. If chilled longer, let it sit at room temperature for 10-15 minutes before scooping.
05 -
Preheat the oven to 350°F (175°C). Line baking sheets with parchment paper. Scoop 1 1/2 tablespoon portions, roll into balls, and coat lightly in granulated sugar.
06 -
Place dough balls 2 inches apart. Bake for 10-12 minutes, until the edges are set and the centers still look soft. Cool on the baking sheet for 5 minutes, then move to a rack.