Whisk together the gluten-free flour, baking powder and salt and stir into the brown sugar mixture. When fully blended, stir in the nuts. Scrape the batter into the pan. If using sea salt, sprinkle some flakes on top before baking. Bake for about 20 minutes.
https://www.cookiemadness.net/2023/01/28/gluten-free-charleston-chewies/