Make ahead of time. Brownies will last 3–4 days in an airtight container at room temperature. They will last up to a week if stored in the refrigerator.
Cutting tip. Do you ever have trouble cutting your brownies into clean lines? Sometimes the brownies will tear or bunch up if you are trying to cut them with a regular knife. Try a plastic knife next time and it will cut through the brownies like butter. So smooth, and way less mess!