I am making a HUGE fondant wedding cake this summer and tried the marshmallow fondant this weekend for a test run. I have not had any classes in fondant except for about 10 + years ago in a demonstration class using the canned stuff.

Anyway... the MMF was great, tasted good, nice to work with and rolled out nicely, etc. BUT, my cake didn't turn out so nice as in pictures. I need help!

First, what I did was, a two layer round cake, with a crumb coat of buttercream (I let dry overnight) and then another coat of buttercream and then put on the fondant. The shape was very rounded at the edges of the top rather than the nice defined edges I'll need for the cake I'm doing. In addition, the cake got gradually wider toward the bottom... I think that as I smoothed the fondant, the buttercream squished and worked it's way to the bottom... cuz when I cut the cake the buttercream was very thin at the top and thick at the bottom. Thus, I had a somewhat cone shaped cake.

HOW can I make my cakes have nice definied edges and not lose their shape when using fondant? Yikes, I'm scared now!

Thanks,
Mama

It is part of the features of a fondant cake that you get softly rounded edges not sharp edges.

My suggestion is to not use the buttercream crumb coat. In summer, this is going to melt on you and the cake would become a heartbreakingly wrinkly mess.

It might be ok to have buttercream between the layers if you particularly want the taste of buttercream, but for summer, a more heat-tolerant filling would be best, such as preserves, lemon curd etc.

Brush a very thin covering of heated jam on the cake to stick the fondant. This will retain the defined edges.

I find i have to use less buttercream on fondant cakes or it squishes down the sides. Someone mentioned making sure the icing was firm by putting it in the fridge for awhile before covering in fondant. I'm going to try that.