Finely grind the walnuts in a moulinette. Put the rusk in a large freezer bag. Close the bag and crumble the rusk with a rolling pin. Knead walnuts, rusk and butter.
Line the bottom of a springform pan (22 cm diameter) with baking paper. Press in the rusk mass as a base. Place the baking tin in the refrigerator for 1 hour.
Soak gelatine in cold water for 5 minutes. Mix cream cheese with vanillin sugar and sugar. Rinse orange, grate peel and stir into the cream cheese mixture. Squeeze the orange and heat the juice.
Dissolve squeezed gelatine in the orange juice, stir in 1-2 tbsp. cream cheese and then quickly fold into the remaining cheese mixture. Then spread on the cake base and place in the refrigerator for 2-3 hours.
Thaw wild blueberries on a sieve. Carefully dab dry with kitchen paper. Prepare the cake glaze with currant juice and sugar according to instructions. Stir in blueberries and spread on the cream cheese.
Allow the cast to set. Remove the springform ring and place the cake on a cake plate.