Since the Barbie doll is made out of cake, you’ll have a cake board underneath it, so having a middle dowel in the sheet cake for support shouldn’t affect anything. Treat it like you would any other topper.
Whenever I’m placing a heavier topper on a cake, I prefer to use the wooden dowels because they won’t give way and they’re not as intrusive as the bubble tea-straws.
Hope this helps!
DJ - Fun Fiesta Cakes
