When you are placing top tier onto the lower tier, only use the spatula to the point that the front end is resting on the lower tier. Back end of upper tier is just an inch or two above the lower tier. Get the cake positioned correctly on top of the lower tier. Then, remove the spatula, and let the cake gently drop onto the lower tier. (It sounds much, much scarier than how it really is. We’re only talking an inch or so of a drop.) It takes a little bit of practice, but that’s how I’ve done it for quite a while. I do this with both fondant and buttercream cakes. However, with buttercream, both of the tiers must be chilled so the buttercream is very firm.
Hope this makes sense—it’s a little tricky to put into words. The key is not to have the upper tier fully placed onto the cake with the spatula underneath. When you slide the spatula out, even very carefully, you will mark the cake.
