Brownies in a Jar?

[SoldiersWife920]

Does this recipe exist? I tried doing a google search for it but all I found was layering the dry mix and sending it that way. My DH liked the cake in a jar I sent him but if I do it again he wants me to already frost it which it impossible (I think?). So I suggested brownies and he said that sounded good but I am not sure how to make them so that they survive several weeks in the mail. Anybody send these before? It doesn't necessarily have to be in a jar but just a way to send them where they get there still fresh. Thanks for your help!