cake made like a cake pop gone wrong

Hi peeps I need your advice, I made a cake via a mould like a cake pop but with icing… its now stuck in the mould and I was wondering if there was any little trick in getting it out without ruining it?

It’s a plastic jelly mould
I covered the surface in icing
Filled with cake crumbs and butter cream
Flipped onto a board
Went to lift mould off and it won’t budge

Any way to remove with out ruining the cake? It’s for Halloween so it’s a brain shape

Please help