I like Sugarshacks Frosting and am trying to figure out how to make a Chocolate version. Anyone have an idea?

I use Indydebi's receipe but I'm assuming you could do the same with Sugarshacks receipe. I use melted chocolate, cool but still pourable. I use about 1 cup of chocolate chips (before melting). I've also used Hershey's chocolate syrup (the one in the can not squeeze bottle). I have to add a little extra milk when adding chocolate. I just add a little at a time until I "get it right".