2) Beat the egg yolks and sugar in the bowl of an electric mixer fitted with the paddle attachment on high speed for 5 minutes, until very thick and light yellow. Lower the speed to low and mix in the mascarpone until smooth.
3) With the mixer still on low, add 125ml of rum, 60ml of orange juice, the vanilla essence, and the seeds from the vanilla bean. Stir until combined.
4) Pour the remaining 125ml of rum and remaining 125ml of orange juice in a shallow bowl. Dip one side of each ladyfinger quickly in the rum mixture and place them in one layer in a 23 by 28 by 5cm deep rectangular or oval dish. Break the ladyfingers in smaller pieces and dip them in the rum mixture to fill the spaces.
5) Sprinkle half the rum-soaked raisins evenly on top. Pour half the mascarpone mixture over and spread evenly. Repeat the layers of dipped ladyfingers, rum-soaked raisins and mascarpone mixture.
6) Smooth the top, cover with cling film, and refrigerate for at least 6 hours, but preferably overnight. Before serving, sprinkle the top with the shaved chocolate and serve cold.