I am fairly new to cake making and I am doing my first wedding cake. It is a vanilla sponge, buttercream and jam filling. I have coated each layer in Gnash and Icing and it looked lovely.

Over night the bottom layer had slid forward, middle to the side and all layers have bulged, it is now a very wonky cake and looks terrible! I don't have time to re-do the icing because the wedding it TOMORROW!

Is there anything I can to do without having to re-ice the whole thing?

Thank you in advance!

Probably not.

Did you dowel it? I'm wondering why it would have moved so much.

Can you post a picture?

You absolutely can put ganache on a sponge cake - all my cakes are sponge cakes and every single one of them has a decent layer of ganache - I have ganached 6" tall sponge cakes with no support inside and they have been totally fine. The issue sounds like either your ganache was not made using the correct ratios and was therefore too soft, that and perhaps your room was too hot and the ganache melted.

No one has brought up the possibility that the layers were not level when this cake was put together. Were they totally/completely level?