Hickory Farms used to sell cake in a can. Moistest cake you'll ever eat. The key is that the dough is sealed in the can and the can is steamed for a couple hours. No way for moisture to escape.

Warning: Brown Bread is not suited to everyone's taste. I once distributed 12 cans to co-workers in Tennessee. 10 of the 12 came back and told me it was the vilest thing they ever put in their mouths and swallowed. The other 2 loved it. It tastes strongly of molasses.