In a pan, mix the blackberries with all the other ingredients up to and including the dessert wine, cover and cook for approx. 5 mins. Remove the lid and continue to cook for approx. 5 mins. Remove the cinnamon stick, crush the blackberries with a fork.
Mix the mascarpone, yoghurt and icing sugar until smooth, then transfer to a piping bag with a smooth nozzle (approx. 10 mm in diameter).
Place ½ of the sponge fingers (sugar side down) in the prepared dish. Cover with ½ of the blackberry mixture, pipe ½ of the mascarpone cream on top and add ½ of the fresh blackberries. Repeat the layers using the remaining ingredients, finish with the fresh blackberries.