Thank you lovelies for your replies, I had a little look on line as well, and I found a woman that had them in her blog.

She dyed the cream cheese icing and put it inside cooked cupcakes after she had carefully cut a piece out, then covered them with icing and little baby shower decorations

Another suggestion was chocolate mud cup cakes with the same inside and an icing ? On the top

I will post a pic when we decide which ones

So thanks girls your ideas are spot on