I'm making a birthday cake that will be half chocolate half yellow cake.  It's for a friend so flavors are completely up to me they have no preference.  I want to do oreo cookie filling for the chocolate half but am having difficulties thinking of something just as good to put in the yellow cake.  Plain icing seems so boring with oreo filling in the other half.  What sorts of things do you fill your cakes with that don't require refrigeration

Almost any of the fruit fillings would work.  I don't like them straight so I mix mine with bc or pastry pride.  Gives a much better taste.  Also Caramel, I think might be a compliment to the Oreo Cookie

It's hard to suggest not knowing what your likes are:)  I'd go w/a fruit like raspberry or pineapple.  You can mix it w/b'crearm or plain jam.