Do you have any of those nice tin containers we get around Christmas time? I re-use for our Christmas cookies every year. I have a huge collection of these tins we get as gifts. I re use them all the time! I know I have a couple that would definitely hold a cake. Just cool your cake in the fridge, wrap with a nice clear food wrap, then pack it carefully perhaps with a thin cardboard sleeve around the edges. Perhaps others can add what would pack it nicely without damaging the cake. I would think those cookie tins would ship pretty well!
St Louis Missouri