Brown the butter in a saute pan for 8-9 minutes or until amber brown in color. Stir in miso and set aside.
Whisk in the sugars, egg, egg yolk, vanilla, then add the dry ingredients and chopped chocolate.
Fold the chocolate into the dough until just combined.
Scoop into 3 tbsp sized balls and freeze until solid, 20 minutes. Bake at 350 F for 11 minutes and enjoy!