Finely crumble the lady fingers and rusks. Melt butter and stir in the crumbs. Place a springform ring (26 cm Ø) on a cake plate and fold in the butter crumbs
Soak gelatine in plenty of cold water. Mix cream cheese, egg yolks, vanilla pulp and icing sugar. Squeeze the gelatine well, dissolve carefully in a small pot at low heat and fold into the cream.
Whip cream until stiff and fold in with a whisk. Peel apples, remove the core and grate the apples coarsely. Mix apples and lemon juice into the cream. Pour into the springform pan and smooth the surface with a dough scraper.
Cover the cake and place it in the refrigerator for about 2 hours. Wash and quarter the apples for garnishing and remove the core. Cut the apples into slices. Heat lemon juice, some water and 1-2 tablespoons of sugar in a small pot and steam the apple slices briefly in it.
Drain and allow to cool. Roast the oat flakes with the remaining sugar in a coated pan. Take out and let it cool down. Decorate the cake with apple slices, roasted oat flakes and, if desired, with small mint leaves.
Results in about 16 pieces.