AI made a cupcake cake for my niece over the weekend. When I initially frosted it, everything was okay. I dropped it off to my sister's house, went home to change, got back, and the icing had stated to crack. Not only that, but it was sinking in certain areas and there were pools of, what believe to be, butter in the sunken areas. I Was devastated, but my sister and her guests loved it. However, I still want to know what went wrong, so I can fix it before I get another order from someone who ISN'T related to me. I usually make cupcakes and don't have this problem, but I have noticed over the months that sometimes when I store my frosting it gets those polls of butter. Usually, I correct the problem by remixing it and everything's okay after that.
BTW, I live i'm the Caribbean, so it's pretty hot here. I don't know if that has anything to do with it.
What kind of Buttercream is it?
Is it all butter or do you add shortening?
It's american buttercream
it's all butter
Tell the process of how you make your butter cream and the recipe and then we can try and help from there. Hard to tell from just what you posted what might be going wrong.