I am guessing that you have too much liquid and curdled the batter. But I am a terrible baker and am probably wrong in my assumptions. Here in Wisconsin I usually remedy the problem with a couple two-three beers and keep er movin!

That was also my 1st thought.  It looks to me to have too much liquid and not mixed well together.  To help more we would need to know the exact recipe and mixing method used.

I am glad you guys have an idea, theanadian160 and kakeladi, because I am clueless and would like to know the answer myself.