Brookie Cookies

For the chocolate chip dough, brown the butter in a saucepan over medium heat until golden and nutty. Transfer to a bowl and chill for about 10 minutes, until soft but not liquid.

Whisk together flour, cornstarch, baking soda, and salt. Beat the browned butter with both sugars until light and fluffy. Mix in the egg, egg yolk, and vanilla. Stir in the dry ingredients just until combined, then fold in the chocolate chips. Chill while making the brownie dough.

For the brownie dough, beat the butter and both sugars until light and fluffy, about 2 minutes. Add the egg and vanilla and mix well. Sift in the flour, cocoa powder, baking soda, and salt. Mix just until combined, then fold in the chocolate chips. Chill for 10 minutes.

Preheat oven to 350°F (175°C) and line baking sheets with parchment.

Scoop about 1 tablespoon of each dough. Press the two doughs together, then roll into one ball. Place 2 inches apart on the baking sheet.

Bake one sheet at a time for 8–9 minutes, until the edges are set and the centers still look soft. Cool on the pan for 5–10 minutes, then transfer to a cooling rack. Finish with flaky salt, if desired