looking for a substitute for liquor in a cake recipe
If your objection is merely to using liquor then I would suggest Brandy Extract, technically, yes it does contain a wee bit of alcohol, like all good extracts, but it is inconsequential. (There are several good Brandy Extracts, the link is provide as an example, not an endorsement) 

If you are simply 'out of brandy' and seeking a substitute, Whiskey or Bourbon would likely carry the closest flavor profile.