Bring the orange and lemon juice to the boil and add the frozen fruits. Boil everything once. Then add the sugar and stir. Take the berries off the heat and let them cool down.
In the meantime, line a rectangular shape with the biscuits and spread the berry-juice mixture over it.
Now whisk the egg liqueur with the mascarpone and vanilla sugar. Whip the cream until stiff and fold it carefully into the mascarpone cream. Then spread this cream on the berry compote. Then put in a cool place for approx. 3 hours.