Almonds, Lemon & fresh Elderberry Juice

Whenever I travel to Italy I try to bring new recipes from there so that I can share them with my supperclub guests.
 From Sardinia I have brought an almond tart recipe which I slightly adapted with a freshly prepared elderberry juice.

The dough:
 zest of one untreated lemon
 4 eggs
 100 g chopped almonds
 80 g sugar
 1 teaspoon vanilla
 50 g vanilla sugar
 50 g flour
 1 teaspoon baking powder
 4 tablespoons lemon jam (no lemon curd)
 1 pinch of salt
 
 The icing:
 2 tablespoons lime juice
 150 g icing sugar
 2 tablespoons elderberry juice (otherwise lime Juice
 1 pinch of salt
 
 Preheat the oven to 160 degrees.

Separate the eggs, beat the egg yolks with sugar, vanilla sugar plus vanilla and salt until fluffy. Mix the flour with baking powder and fold into the fluffy egg mixture with the lemon zest and chopped almonds. Beat the egg white until stiff, add 1 tablespoon of lemon juice. Fold the mixture carefully and slowly into the dough. Fill the dough into a baking tin and bake for about 35 - 40 minutes. Let it cool down. Wipe together the ingredients for the icing and spread on the cake. Serve with an Italian desert wine - Vino Santo from Umbria or Trentino.