01 - Place the chopped dark chocolate in a heatproof bowl.
02 - Warm the heavy cream in a small saucepan over medium heat until it begins to simmer; avoid boiling.
03 - Pour the hot cream over the chocolate and let sit undisturbed for 2 minutes to soften the chocolate.
04 - Whisk gently until the mixture is smooth and the chocolate has fully melted.
05 - Incorporate the butter and vanilla extract by stirring until fully blended and glossy.
06 - Cover the bowl with plastic wrap and refrigerate for 2 hours until the mixture firms sufficiently to scoop.
07 - Scoop approximately 1 tablespoon of ganache and quickly shape into balls by rolling between palms. Place on parchment-lined baking sheet.
08 - Roll each formed truffle in unsweetened cocoa powder to fully coat.
09 - Sprinkle a pinch of flaky sea salt atop each truffle.
10 - Store truffles in an airtight container refrigerated up to one week. Serve at room temperature for optimal texture.