These muffins have two things going against browning. They're made with almond flour, which doesn't brown as easily as wheat flour, and they are sweetened with stevia, so they don't have sugar or honey to promote browning. They do become golden brown at the very last stage of baking. In my oven, I bake them for exactly 24 minutes. They're actually done after 22 minutes according to the toothpick test, but I leave them in the oven for a couple more minutes. This allows them to brown without drying them out. But I wouldn't bake them for longer than 25 minutes, or they could dry out.