1970 — J. Spencer Grendahl, The Mad Dog Press Archives, G. P. Putnam's Sons (1970), page 103:
"We got into that scene a few times, fudge, pot brownies, kef cake. Nice."
1972 — Michael Rossman, On Learning and Social Change, Random House (1972), ISBN9780394480824, page 275:
This fall a free university of 1,000 students has formed, hippies are passing out pot brownies on the main quad, and student government and off-campus people are preparing an ed reform center to knit together regional work.
I especially enjoyed tripping while being interviewed on TV — from a pot brownie for Mike Douglas to magic mushrooms for Tom Snyder — and so, one hour before the "Tonight" show began taping, I swallowed that week's withdrawal of LSD from my bank vault.