Individual cake holders for lunch boxes

[ICanTuckMyBoobsInMyPockets]

Does anyone have any ideas how to put cupcakes or a slice of cake in a lunch box without the icing/buttercream going everywhere?
Had a look on Amazon and they do plastic tubs that look like they're for shops, and they come in 50s, I only want one!

Anyone come up with anything?

Can you not just hunt out appropriately sized tupperware - rather than a 'specific cake box' ..... I have a small rectangular clic-lidded box which works for slices/bars - and a deeper squarer one which is passable for a cupcake - I don't tend to send ones with lots of buttercream on though.

Lakeland have some interesting bits in their food storage and lunch box sections.

In the range they have individual cupcake holders ??