I need to do a cake that is gold fondant. how do I achieve this?

Have you considered using a yellow fondant and then spraying it  gold?  I don't know the size of your cake or the look you are going for but you might want to test this out. Maybe test it by using a white fondant and a yellow fondant.  I used the silver spray on top of black fondant when I wanted a  metal look for a robot cake and I was very happy with the results.

Good luck!

Theresa

AI don't have an airbrush, so normally I paint yellow fondant in gold dust if I need it to be gold. If it just needs a gold shine n you can mix the dust with vodka and brush it on. You can even cover it in gold leafs. Real gold. They are cheap and eating gold doesn't do any harm, but personally wouldn't want that texture in my mouth in hug amounts.