How to use a cake pan as a key hideaway?

Make a couple of decorative paving stones with a hollow underneath for keys

Ok now I am curious, I have never heard of this. 🤔

I do not understand the question? I suspect there is a typo, or incomplete question.

you use the cake pan as a mould for a stepping stone. You put a small plastic box in the middle of the concrete. When the con Crete is cured the stepping stone gets slipped out of the mold and the plastic box is removed as well. This leaves enough space for a door key. You put the hole side down.

http://www.hometalk.com/diy/outdoor/garden/diy-stepping-stone-with-secret-key-hider-24101065

Good idea!

Great idea!