Place chopped chocolate in a heat-proof glass or stainless steel bowl.

Heat heavy cream in a small saucepan over medium heat until it reaches a gentle simmer (80°C/176°F).

Pour hot cream over the chocolate and let sit for 5 minutes without stirring.

Gently whisk the mixture from the center outward until a smooth, glossy emulsion forms.

Stir in the softened butter and hazelnut liqueur until fully incorporated.

Cover the ganache with plastic wrap pressed directly onto the surface and refrigerate for 2 hours or until firm.

Using a small scoop, portion approximately 15g of ganache and press one whole roasted hazelnut into the center.

Roll into a uniform sphere between your palms.

Immediately roll the truffles in the finely chopped hazelnuts or cocoa powder to coat thoroughly.

Store in an airtight container in a cool environment or refrigerator.