Clean, wash and cut the rhubarb into pieces. Peel, halve and core the apple and cut it into slices. Put 150 ml juice, 75 g sugar, vanilla pulp, rhubarb and apple slices into a pot, bring to the boil, cover and simmer for 4-5 minutes. Stir cornflour and 4 tbsp. juice until smooth. Stir into the boiling groats and bring to the boil briefly.
Let it cool down. Wash the orange and grate dry. Finely grate the orange peel. Halve the orange and squeeze the juice. Soak the gelatine. Mix sour cream, quark, orange peel and 100 g sugar. Put half of the biscuits in an ovenproof dish (9 x 20 cm; 6 cm high). Sprinkle with half of the orange juice. Pour the groats over them. Squeeze out the gelatine, dissolve and mix with approx. 3 tbsp. quark cream in the pot.
Put half of the biscuits in an ovenproof dish (9 x 20 cm; 6 cm high). Sprinkle with half of the orange juice. Pour the groats over them. Squeeze out the gelatine, dissolve and mix with approx. 3 tbsp. quark cream in the pot. Then stir into the rest of the cream. Spread half of the cream evenly on top. Press the remaining biscuits into the cream, sprinkle with the rest of the orange juice. Add the rest of the cream and smooth it down. Chill the Tiramisu for about 2 hours. Sprinkle with pistachios
Then stir into the rest of the cream. Spread half of the cream evenly on top. Press the remaining biscuits into the cream, sprinkle with the rest of the orange juice. Add the rest of the cream and smooth it down. Chill the Tiramisu for about 2 hours. Sprinkle with pistachios
waiting time approx. 3 hours