Get yourself a medium deep bowl or dish about 8-10 inches in diameter and arrange your ladyfingers snugly in layers on top of each other. Sweeten your coffee with 2 tablespoons of the sugar. Pour the coffee over the ladyfingers, making sure the top layer is completely covered — you'll see the coffee being sucked up by the ladyfinger. While that's soaking, put your mascarpone into a bowl and whisk it up with the rest of the sugar.

Score the vanilla beans lengthwise and scrape the seeds out into the bowl of mascarpone, keeping the beans for making vanilla sugar if you want to. Continue whisking and as you do so, drizzle in the vin santo or sherry. You want to get the mixture to a loose, shiny consistency. If it's still too thick you can use a little of the orange juice to loosen it before you squeeze the rest of the juice over the ladyfingers. Smear the vanilla mascarpone over the ladyfingers and either grate all the chocolate over it or make shavings using a knife or a peeler. Sprinkle lightly with a little finely grated orange zest and keep in the fridge until you're ready to serve.