For the plum compote, wash plums, halve, stone and cut into slices. Wash the orange hot, grate dry and peel the skin of 1/4 orange thinly. Use the remaining orange for other purposes.
Heat 40 g sugar and cinnamon stick in a saucepan and let it caramelize. Deglaze caramel with 300 ml nectar. Add orange zest and vanilla sugar. Simmer for about 5 minutes until the caramel has dissolved.
Stir the remaining nectar with starch until smooth, add and bring to the boil while stirring. Add plums and simmer for about 1 minute at low heat. Remove cinnamon and orange peel from the compote.
Pour the compote into a bowl and let it cool down.
In the meantime, separate the eggs. Beat the egg white with salt and 5 tablespoons of cold water in a mixing bowl until stiff, adding 150 g of sugar. Stir in egg yolks. Mix flour with 1/2 tsp. cinnamon and baking powder.
Sieve onto the egg foam mixture and fold in carefully. Pour the sponge mixture into a piping bag with a large perforated spout. Spray 18-20 strips (each approx. 6 cm long) onto a baking tray lined with baking paper.
Leave a gap of about 2 cm between the dough strips. Fill the remaining dough into a springform pan (20 cm Ø) lined with baking paper. Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see
manufacturer) bake for about 15 minutes. Push the tray with the lady fingers over the springform pan and take it out of the oven after about 15 minutes, let it cool down. After about 15 minutes of baking time, slide the sponge cake in the springform pan into the middle shelf and continue baking for about 3-4 minutes.
Remove and let it cool down.
In the meantime soak the gelatine in cold water. Finely puree 300 g compote. Whip mascarpone with curd and 40 g sugar for about 2 minutes. Stir in the pureed compote. Squeeze the gelatine well and heat up with 2 tbsp. cream in a small pot until the gelatine has dissolved, add to the remaining cream and mix well.
Cold. Remove the springform pan from the sponge base. Remove baking paper. Place a cake ring around the sponge cake base, pour in cream and refrigerate for about 3 hours.
Carefully loosen the cake ring. Place the lady fingers around the cake and press firmly. Spread plum compote over the Charlotte. Arrange Charlotte on a plate and sprinkle with cinnamon.