The cake is chocolate and it's covered in buttercream. I smoothed the icing used the VIVA method. And of course, the other accents are fondant.
The guitar is made with royal icing. I found a template online and just traced it on the wax paper. Then, I added some confectioner's paint and buttercream to decorate it.
Here is the smash cake I made to match it. I didn't put too much fondant on it so it would be much easier for the little girl to eat and not get choked or anything like that.
I really enjoyed this cake! =]