Can You Dehydrate Brownies By Overcooking?
Agree that they likely won’t go bad when baked normally… they’ll start to dry out or get crusty on their own after several days or a week.
But if you’re interested in trying something different, I’ve had these bookmarked forever: http://www.cookiemadness.net/2012/10/brownie-bark/
These aren’t brownies, but I’ve made cookie brittle a dozen times Reading More May Cause Envy…