Sounds delicious! Can't wait to try it, but can you tell me if this would have to be refrigerated once placed in a cake? The evaporated milk throws me off.

This should be refrigerated. Evaporated milk needs refrigeration after it is opened.

I've been trying to find a chocolate sauce to fill a cake with that will be almost like chocolate milk type syrup.....something really gooey. Does this filling harden like fudge? Or will it be gooey when you cut the cake open?

I would like to know also if this is a thick filling.