Previously:
In the 60s, the "Space Race" was in full swing, ushering the United States and the Soviet Union into an era of innovation and discovery. While the nations' eyes were on the skies, space was not necessarily the final frontier as terrestrial adventurers were still making discoveries of their own. Two years before the crew of the Apollo 11 touched down on the moon, the crew of the S.S. Guppy made landfall on Crunch Berry Island.
And it didn't take the gallant Cap'n and crew long to discover the island's most delicious natural resource. It was young Brunhilde who first found the exotic yet delicious looking vegetation. And just as quickly as she found the Crunch Berries, she started consuming them. Bold? Yes. Irresponsible? Definitely. But fortunate favors the irresponsible.
A couple of interesting things of note are mentioned in this commercial. First, apparently Crunch Berries are automatically crunchy right off the bush. That would be a red flag for me but it doesn't slow the Cap'n down at all. They also "Taste like strawberries" according to crewman Dave. At least that's what I think he says. He has a weird way of pronouncing "strawberries" though so there's still some nagging doubt in the back of my mind. He says it twice in one commercial which is odd as I don't remember Crunch Berries ever being described as tasting like anything other than "Crunch Berries."
Also, the Cap'n mentions being eager to "tell the folks at Quaker" of his newfound snack. This seems to clarify that the Cap'n and his crew are not attached to a specific Navy but instead are having their voyages financed by Quaker Cereals with the goal of finding delicious new breakfast flavors. But that's not the only things they found.
Behold the Crunchberry Beast! Though it's not explicitly stated in his commercial debut that the creature hails from Crunchberry island, it is pointed out that his diet consists of nothing but Crunch Berries so I think we can put two and two together here. While CB seems like the kind that would chafe at the domesticated life, as long as he's provided with a steady stream of his favorite food he maintains his position as a loyal part of the Cap'n's crew.
All this useless information serves as an in-canon origin for the sweet breakfast treat and one of the more successful of the Cap'n's mission as he was able to supply his patrons with a new breakfast flavor and provide himself with a new monster/crewman for future missions. As usual, the Cap'n makes it happ'n.