Cake-in-a-jar (CIAJ) is a safe way to store prepared cake for a long period of time using mason jars. If prepared properly, CIAJ will last for several months at room temperature, and even longer refrigerated.
Use pint wide mouth mason jars. Jars should be clean and free of chips in the glass. Seals (the flat lid) should be boiled to kill bacteria and to saturate the rubber seal.
Preparation is very easy. Simply prepare the batter from a mix (or from scratch if you prefer), and put 1 cup batter into jars. Put jars on a cookie sheet (to prevent them from tipping over on the wire rack in the oven) and cook following normal cooking instructions for the mix you used.
Use a long toothpick to ensure that the cake is done. Generally you want the cake to be a pinch drier than normal, as steam that is normally lost from the cake will be held in by the mason jars lid.
Once done cooking, carefully clean the mouth of the jar so that it is free of any crumbs (to ensure a good seal), put on the seal, and loosely screw on the band. Allow to cool.
Jars properly prepared last at least a month. I recommend putting a one-month expiration date on the jar so you don’t accidentally eat a crazy old jar of cake.
Corn Bread in a Jar
So I’m trying corn bread in a jar right now. One box of Jiffy Mix only makes about 1 1/2 cups of batter, so to get the same as a normal box of cake mix you’ll need to use 3 or 4 boxes of Jiffy Mix.
Looks like it turned out ok. Tastes ok, but of course corn bread is tastier warm so the jar is probably just best as a replacement for a muffin pan if you don’t have one.
Have a friend living far away? Send them CIAJ and a can of frosting for birthdays and holidays.