Aging a brandy in a glass.

My friend has a newborn son. As a gift, I want to give him a wax sealed glass of brandy so he can open it on his 18th birthday. I’m a complete noob in this regard so I’m looking for some advice.

Any ideas on how to make it a bit interesting? What is your guys opinion on throwing in a bunch of walnut wood. Is it gonna taste good after aging for 18 years in a glass bottle that way? Another question is: Would there be any difference in putting the brandy in a bottle with a cork lid or just a regular screw lid.

Thank you very much for your insight.