I have been asked to do a 3 tier b-day cake covered in buttercream with fondant diamonds and stripes. Can I do this? I'm afraid the fondant is going to slide down the cake. Please Help!
If your buttercream crusts and is stable you will have no trouble. Every cake I make is iced in buttercream with fondant accents.
Normally I just brush some water on the back of the fondant pieces and stick them to the cake. If you are that worried you can use a spot of royal icing or a dab of buttercream.
i use smbc, which does not crust, and i use fondant decorations all the time.
i chill my cake, bring it out and apply decorations while still chilled.
i do not need to add anything to make them stick...the buttercream itself is the "glue". i smooth them down with my fondant smoother or my fingers (whichever works best for that decoration/placement). if the buttercream starts to get too soft (appliques can be difficult to apply on soft buttercream), i pop it back in the fridge to firm it up, and then resume applying my fondant decorations. they stay where i put them and do not move even when the cake warms up.