I'm hoping you guys can talk through a cake structure with me. In 2 weeks, I have a 10" bottom (topped w 8" sps) and 8" middle (topped with 6" sps) 4" styrofoam spacer topped with a 6" ball. I'm not worried about the 8 and 10 inch, my question is for the spacer and the ball on top. I'm worried about the ball shifting since it's baked in 2 pieces, so I was thinking of drilling through the top of the 6" sps plate and pounding a center dowel though the ball and styrofoam into the hole in the sps plate.

Would that work? Is there a better way? I need to try to transport this cake stacked, the styrofoam spacer will be covered with fondant to make it look like part of 8" tier mountain, so I can't put the spacer and ball on when I get to the venue.

Am I over-thinking this?

Thanks for your help!

I just made a ball cake and the customer wanted me to make sure the ball would not roll off the other tier it sat on.  I did it just the way you described! I drilled a hole in the board the ball sat on and pushed a dowel through into the bottom tier. It worked great! I 

AThank you!! I just don't want it to shift during transport. My other option would be to lose the 4" spacer and set the ball on the 6" sps itself. Decisions, decisions!

I think it'll be just fine the way you described! I also had a foamcore board as my cake board and I also pushed the dowel down into that board as well.  It wasn't budging!