Mix the coffee and muscovado sugar together, stirring until the sugar dissolves. Set aside to cool, then stir in the marsala.

Meanwhile, beat the mascarpone, vanilla, caster sugar and milk together until smooth using an electric whisk. In a separate bowl using the same beaters, whisk the cream to soft peaks. Gently fold this into the mascarpone mixture.

Set aside 4 tbsp of the coffee mixture. Dip a third of the sponge fingers into the remaining coffee mixture and use them to line the base of a 1.5-litre glass dish – a rectangular one is easier, but any shape will work, you may just need to break some of the sponge fingers to fit. Spread over a third of the mascarpone mixture and scatter over half the blackberries. Repeat the layers, finishing with the mascarpone. Sift over the cocoa or sprinkle with grated chocolate.

Chill for at least 3 hrs. Will keep chilled for a day. When ready to serve, gently warm the reserved coffee mixture with the chopped chocolate, stirring until smooth. Spoon some of the warm sauce onto serving plates and top with a scoop of tiramisu.