Hello, I think I can help you. I made this cake last night for the first time ever and it turned out amazing! I baked 2 cakes in a rectangular sized pan, iced them in between and then iced the whole cake with buttercream. As for the boobs. I used a small stainless steel bowl, the equivalent of a real DD size breast, I buttered the bowls and filled them with freshly made rice crispies. I removed them from the bowls, placed them on the cake.. Frosted them with the butter cream and then cut out the shape of the curves of a womans torso. Then I covered the whole cake with a thin marshmellow fondant. It looks great and the boobs are very sturdy!
Hope this give you some sort of idea :)
Hope this give you some sort of idea :)