Each bar is wrapped in cellophane, which are then wrapped in the normal outer packaging. To make the 4 pack, they simply took 2x two packs and put them on a cardboard tray,and then wrapped those.
I don’t think I’ve ever gone through so much unwrapping for candy.
They’re still in foil in the UK.
And US
TIL it’s only Canada that switched
https://en.wikipedia.org/wiki/Cadbury_Creme_Egg
TIL Canada switched to plastic wrappers