I tried making my first carved cake the other day from 6- 9 inch rounds stacked. I put dowels in after my third layer and put a cake board on top. Then I put my next layer of cake on top of the board and continued filling. My issue was the cake board in the center of the cake. The center board created about a 1/4 inch space between the layer where the support was. Am I using too thick of cake board? How do I creat a flush/seamless appearance. I also had huge air pockets after applying the fondant. Could the gap in space have created this?

Trying to understand, you doweled the three layers and then you placed a cake board directly on top or did you leave a gap? You should place the board directly on top of the layer. Okay, you torte/ice your cakes regularly and then you cover them with fondant and then you insert the dowels. Then you top the board with the next part of layers and continue... Or, torte/ice the first three, dowel, place the board and continue layering the 4th, etc. Then you ice them all together and make the edges smooth/uniform/aligned all over and cover all with a layer of fondant. Hope I'm clear! You can PM me!

Your dowels should have been flush with the top of the cake...there should have been no air pocket between the cake, the cake board, and the next sets of cake.

Also the best thing is to add supports every 4" so for 6 rounds, you should have had basically three sections of cake.

After a couple of layers I placed 4-5 dowels in a circle pattern then put the cardboard round on top of that. My cardboard round was smaller than the actually cake because I was carving in an hour glass shape. I placed a little buttercream on the board to secure the next layer. This is where the gap came into play.

Fill the gap with icing before you put on your fondant

Thank you everyone for your suggestions. I will try this the next time.