If your coffee liqueur is on the sweet side, then add six drops of vanilla bitters to help the balance and complexity. However, with a good coffee liqueur...
No no no, use tequilla blanco instead of gin and then taste. I just compared the two and I am in no doubt. The coffee liqueur was Galliano Espresso. Does that cocktail exist? What's the name? Brave Succulent or Brave Cactus?