I have watched several videos on stacking cakes, and visited wilton.com. So I have a really good idea on how this is done. I was wondering can this be done for a 11x15 rectangle cake frosted in Whip cream (thick layer) and a 6 or 8 inch round cake sitting on top. If I cut my dowels up to the point where my frosting ends will it hold the wait of the round cake so it doesn't sink into my frosting. Your help is greatly appreciated.

Yes it will, just be sure that your dowels are cup perfectly even.

I've done it many times without issue. Of course, the cake does need to be refrigerated because of the whipped cream topping.

Good luck!
Deb