In the 1940s and 50s, the licensing of Donald Duck for food items was quite common. Crackers, bread, and juice were just a few of the things that bore his image. A promotional campaign for Donald Duck Peanut Butter included a series pin-back buttons. Both Snow White and Dopey were among the collection of Disney characters to be issued."© W.D.P."
They are pictured on page 860 of Hake's Official Price Guide to Disney Collectibles, 2nd edition, 2007.
See a few vintage advertisements for Donald Duck Peanut Butter at the Gallery of Graphic Design. And learn more at the Disney Food Blog.