It's possible to use concentrated liquid coffee, but that brings the potential of over-thinning the sauce. Consistency is key ...

However, if you switch out the cream in ganache for corn syrup, it becomes a rich chocolate sauce that stays liquid and flowing. It's very similar to hot fudge, without the time and effort ...

This will take between 2 to 4 minutes, depending on your speed and strength. Use the sauce immediately.