Roll level tablespoons of the mixture into balls; place on baking-paper lined tray. Refrigerate balls while preparing the coating.
Place extra dark chocolate and oil in a medium heat-proof bowl. Place bowl over a pan of simmering water; stir until melted. Using a fork or skewer, dip balls into chocolate mixture; drain off excess. Return balls to tray. Refrigerate for 15 minutes or until chocolate is set.
Spoon warm white chocolate over top of puddings; decorate with marzipan leaves. Refrigerate until set.