Chop chocolate bar into small chunks and place it in a bowl. Add butter + coffee granules + sugar + salt and keep aside.
Add heavy cream to a sauce pan and bring it to gentle simmer. Do not let this boil. Pour this into chocolate. Wait for a minute and mix it gently with a whisk to avoid air bubbles. It will come together like a ganache.
Keep it outside approx 10 minutes before serving. If needed, you can top with lightly whipped cream, chocolate shavings and berries.
Use a good quality chocolate. You can do the same with white chocolate too.