I did a two layer 6" round "Hotwheels" cake for my friends son who turned 4! I did cupcakes as well. They all loved it. This is th 3rd cake I have made so far and I am still trying to get the hang of covering the cake with fondant. I ALWAYS get gathers at the bottom, how can I fix this problem??? I currently use Choco pan, I am not sure if this makes a difference?!
It's just a technique thing... as you smooth the fondant down the sides, be attentive to spread out any gathers as you go, working down from the top.
You have to kind of lift the sides like a tablecloth as you smooth down the sides with the side of your hands. It will work thje pleats and folds out as u go around. HTH
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Are you rolling out enough fondant? Sometimes it helps to have more extra fondant that drapes over - easier to smooth out the wrinkles at the bottom...
I like to put my cake on top of a bowl or something that is smaller than the cake and off my counter so that the fondant hangs down off the cake. That makes it WAY easier to smooth.