Wash, clean and cut the rhubarb into pieces (approx. 1 cm wide). Wash, clean and quarter the strawberries.
Bring 125 ml rhubarb juice and 1 tablespoon sugar to the boil. Add rhubarb and simmer for about 4 minutes. Remove the rhubarb pieces. Stir starch and 1 tbsp. rhubarb juice until smooth. Boil up again, add rhubarb and strawberries and let cool down while stirring occasionally.
Stir mascarpone, 1 tablespoon rhubarb juice, 2 tablespoons sugar, vanilla sugar and 1 tablespoon raspberry brandy until smooth. Whip cream until stiff and fold into the mascarpone. Cut the lady fingers into pieces. Pour 2/3 of the compote into 4 glasses. Set 8 Amarettini aside. Break the remaining Amarettini roughly.
Spread the lady fingers and broken amarettini on the compote. Mix the coffee and 1 tbsp. raspberry brandy and sprinkle on the lady fingers. Add mascarpone cream. Spread the rest of the compote and the amarettini on top