Transfer the batter to your lined baking pan and smooth out the top.
Bake for about 30 minutes until the top is set and a toothpick inserted in the center comes out with a little bit of moist batter. If the toothpick comes out clean, the brownies are over-baked.
Place the baking pan on a wire rack to cool, then transfer to the fridge for at least a few hours. The brownies will get more fudgy and dense as they rest in the fridge.
Notes
1) Walnut Butter: If you have walnuts, you can make your own walnut butter. See my walnut butter recipe.