The Girl With A Curl blog featured these jar cakes that are baked in 1/2 pint mason jars. In the blog posting, there are links to recipes for the Swirled Nutella and the Blueberry Coffeecake cake in a jar. I'm guessing you could use just about any cake recipe you'd like.
Wouldn't these make the cutest bake sale or gift cakes? Read the post at The Girl With A Curl and let me know what you think! :)