Someone at a Christmas Farmers market, where I was getting supplies today suggested Rum or Brandy in coffee. Due to metabolic reasons I can not indulge in alcohol

so anyone willing to be guinie pigs so we can "develop" a new range of coffee liqueurs ?
I was sussing out the competition today at Starbucks (See attached image),where they are doing a coffee and mint, with cream and chocolate topping. So I need to get cracking on that side of things.
If only I had thought to pick up some Christmas pudding coffee