I am making a circus cake this weekend. I am planning on making the top of the circus tent which is 2 layer w/filling 6"round cakes with RKT. Do I need to put a separator plate, dowels, or will the RKT be light enough to just sit on top of the cake. I have not used RKT's yet. Thanks!!

They will be lighter than cake, but my motto is "better safe than sorry". I'd dowel and support it just to cover all the bases.