I know there's a lot of posts out there on this but I'm in a time crunch!

I'm working on a cake tonight and will be making 2"x2" fondant decorations and want to apply them to a cake frosted in ABC. The BC itself has crusted. The fondant pieces shouldn't be too heavy but does anyone know if it's necessary to let my fondant decorations dry for a couple of days before putting them on the cake? I really plan to let them dry more like 1 hour, then stick them on there. If that's too risky I'll pipe the decorations out of BC. Thanks in advance!!

If its not necessary for the fondant decorations to stand out/up from the cake, you can simply wet the back side of the fondant and apply them to your crusted BC. If that won't stick, try using a little edible glue (tylose & water mixture). HTH!

you can stick fondant to crusted ABC with a tiny dab of water, lemon extract, vodka, piping gel, and i even use buttercream. (i do work on cold buttercream cakes though, if the ABC is a soft room temp, then the buttercream may be too heavy)