I did a milk chocolate ganache to top my coffee cupcakes and it looks 'ok' under normal light but I'm a little worried.
I understand that sometimes the ganache can go wrong by 'separating' into an oily muck.
Mine hasn't quite separated into something like that, but under direct light, instead of an even glistening top, it looks more like there's a very thin film of oil.
I'm not sure if this is from the butter in my cake or if the ganache has started separating.
I've circled it to show you what I'm talking about.