Place the chocolate into a heatproof bowl.

Pour the heavy cream into a saucepan and add the instant coffee and salt. Heat the cream over medium heat until it starts simmering. Remove from the heat and whisk to dissolve the coffee granules.

Pour the cream mixture into the bowl with the chocolate. Stir until the chocolate has melted and the mixture has a homogeneous consistency. If still hot, allow it to cool down until warm to the touch.

Add the butter and stir to incorporate. Additionally, you can blend the mixture with an immersion blender to ensure there are no pieces of chocolate and butter left.

Cover the ganache with plastic wrap, ensuring the wrap touches the surface, and refrigerate for a minimum of 6 hours or overnight.

Take the ganache out of the fridge and stir until slightly softened. Then, transfer it into a piping bag and pipe it, or use it as desired. You can also whip this ganache for 1 minute or until soft peaks form to achieve a fluffy texture. Be careful not to overwhip it!