I made this cake using 9 cups of RKT and it is much heavier than I thought. I'm going to place it on top of two 10in. rounds.
I'm going to use dowels for the two 10 in. rounds, but do I also need to put a dowel through the purse and down through the 2 cakes?
Do I need to put a cake board under the purse?
If I should use a dowel with the purse, any tips on how to do it without messing it up since I already covered it in fondant?
No, you don't need the center dowel. Use a cake board under the purse, slightly smaller than the bottom. This way it stays hidden and helps to distribute the weight between the purse and the dowels under it.
You said it is quite heavy. This could mean that the weight itself will hold the purse at its place. But to be safe, put dab of buttercream or RI between the purse and the cake board and between the cake board and the cake under it. It will work as glue and helps to hold it together - this is mostly for the transport and handling of the whole cake, especially when you at a time loose control over it (don't deliver it yourself etc.)
i too would put the purse on a board & dowels in the 10" to support it. Use an angled spatula & go around the bottom edge to make sure it's loosened & then lift w/ the angled spatula or a cake lifter.
Great, thank you so much for the replies!