Brown butter, also known as beurre noisette is simply butter that has melted, and then cooked a step further so that the milk solids in the butter caramelize. This gives a wonderful caramel flavor to the cookie dough.
Leave the butter to cool to room temperature then add in - brown sugar -granulated sugar -egg -vanilla -espresso powder -salt -flour - baking soda - chocolate chips
Roll the cookie dough into balls using around 2 tablespoons of dough for each. Space them out generously on parchment paper-lined cookie sheets. The cookies will spread in the oven, so give them plenty of space to do so.
Bake the cookies for around 11-12 minutes until they have puffed and the edges have cooked. The cookies will seem very soft, will continue cooking a bit on the hot oven tray once out of the oven, and will firm up as they cool down.
Sprinkle with flaky salt while the cookies are still hot. Swipe up for the full recipe!