A little browning on the matcha cookies is okay. It actually adds a nice caramel flavor. But if your matcha cookies get too brown, your oven may be too hot or you're baking the cookies too close to the heating element. Make sure your cookies are baked on the middle rack and the oven temperature is at 375°F. Some ovens may run a little hotter, so we recommend using an oven thermometer to be sure.