Place lavender and heavy cream in a small saucepan over medium‑low heat; simmer gently for 5 minutes, stirring occasionally. Remove from heat and steep, covered, for 15 minutes.

Strain cream through a fine‑mesh sieve into another saucepan or bowl, discarding lavender buds.

Reheat lavender‑infused cream until just simmering. Pour over chopped dark chocolate in a heat‑proof bowl and let sit 2 minutes to melt.

Add butter and vanilla extract; stir gently until the mixture is smooth and glossy.

Cover and refrigerate ganache for about 2 hours, until firm but scoopable.

Use a small spoon or melon baller to scoop tablespoons of ganache. Roll quickly between lightly buttered or gloved hands to form smooth truffle balls.

Roll truffles in cocoa powder, finely chopped lavender, or white chocolate shavings to garnish.

Place truffles on a parchment‑lined tray and refrigerate 15 minutes to set. Bring to room temperature before serving for best flavor.