According to The Elementary School Rumor Mill, only two things were ever going to survive a nuclear war: cockroaches and Twinkies. With a legendary shelf-life nearing that of plutonium, acquiring Twinkies was often a goal on any apocalyptic survivalist's To Do List. Case in point:
Family Guy's "Da Boom" episode took place after a nuclear exchange destroyed the world. As the Griffin family wandered the wastelands, Peter -- remembering that Twinkies can withstand such a disaster -- made it his mission to get the family to the Twinkie factory in a nearby town. When they got there, they saw that the golden spongecakes had indeed survived, feeding them all for years. A new post-apocalyptic village arose around the Twinkie factory ruins.

Apparently, store shelves have been laid bare upon the news, so if you haven't had a Twinkie in a while, you probably missed your chance. And there won't be any after the End of the World either.
(And truth be told, I'm a Zingers man anyway.)