I love black licorice. It's is a very Dutch thing. We eat tons of it in our nation and I am personal responsable for a great part of that.
But I don't know of any recipe that resembles the taste of it in something like cake or buttercream.
I cannot image it wil taste good..
We use it in a cough syrup.
Anise is a little bit alike, though not the same. Absint has this anise flavour.