01 - Place the chopped dark chocolate in a medium heatproof bowl.
02 - In a small saucepan, heat the heavy cream over medium heat until it just begins to simmer without boiling.
03 - Pour the hot cream over the chopped chocolate and let rest for 2 minutes to soften.
04 - Gently whisk the mixture until smooth and glossy.
05 - If using, add the unsalted butter and vanilla extract, stirring until fully blended.
06 - Allow the ganache to cool slightly before pouring over cakes or glazing. For a thicker consistency, cool longer or refrigerate until desired thickness is achieved.