Finely chop the chocolate and place it in a heatproof bowl. Heat the heavy cream in a saucepan over medium heat until it simmers. Pour it over the chocolate and let it sit for 5 minutes before stirring until smooth. Mix in the butter, vanilla extract, and a pinch of salt. Cool for 30 minutes, then refrigerate for about an hour until firm but scoopable.

Scoop small portions of the chilled filling and roll them into 1-inch balls. Create an indentation at the top of each ball for bunny ears. Place on a parchment-lined tray and chill for another 20 minutes.

Melt the remaining chocolate until smooth. Dip each chilled truffle into the melted chocolate, tapping off excess. Place back on the tray and allow to cool, or refrigerate until set.

Prepare melted white chocolate for decorating. Pipe bunny ears and features onto each truffle, attaching edible eyes and sprinkles.

Let the decorations harden for 30 minutes at room temperature before serving. Store leftovers in an airtight container in the fridge for up to one week.