Brown 225g butter on medium heat until deep amber. Pour into a glass or stainless bowl, scrape every milk solid. Chill until solid.
Cream solid brown butter, cold cubed butter, and sugars just until combined.
Add eggs, yolk, and vanilla.
Whisk dry ingredients separately.
Fold dry into wet.
Fold in chocolate chips and chocolate bar.
Scoop into 100g balls.
Chill 1 hour minimum.
Bake at 375F for 12 to 14 minutes.
Slam the tray on the counter 2 to 3 times the moment they come out.
Flaky salt immediately.
Rest 10 minutes on the pan.
