While they may look like easy gifts to give for the holidays, you don't want to give the gift of foodborne illness!
Bread or cakes baked in canning jars, then applying the lid, can create a low-oxygen environment. This, combined with baked goods high in moisture and low in acid, can support the growth of botulism. Canning jars are not designed to be used in the oven per manufacturer recommendations. Dry heat puts stress on the jars and can cause them to break. The best options? Use oven-safe baking pans for baked goods. Freeze baked goods for later use.
Learn more in these articles:
Food Preservation: Setting the Record Straight on Canning Breads and Cakes