If the cookies start to get dark on top after 15-20 minutes, tent the pan with aluminum foil. This can happen because of your oven – some ovens blow harder on top and can cause them to brown faster (I’ve had this happen with my new oven but not my old one.)
They’ll be dark golden when done; the toothpick test 2-inches from the side of the pan will come out with some moist crumbs attached but not be liquid.
Be sure to use a metal pan for best results.
Store in an airtight container at room temperature or freeze for several months.