Line a baking dish with the ladyfingers. Pour the egg liqueur on top - approx. 3/4 bottle depending on the shape. Let the ladyfingers sit for about a quarter of an hour. In the meantime, mix the sour cream with the preserving sugar. Whip the cream until stiff and mix with the sour cream. Now spread this mixture over the egg liqueur ladyfingers. Spread the red fruit jelly over it.
It is best to let it sit for a night before you eat it.