Quaker Oats hired Paul Winchell to film a commercial for Life cereal, aided, of course, by Jerry Mahoney. Figuring this to be from 1966, and attached to an episode of Bewitched. Hanna-Barbera, which produced the open for Bewitched throughout its run, created the variant attached to the ad, which has Darrin eating some Life. Gary Owens (Space Ghost) is the announcer for the sponsor tag.
Winchell & Mahoney would then do a spot for rival Kellogg's a few years later, shilling for Frosted Mini-Wheats. We'll post that one another day.