Reduce orange and sea buckthorn juice, mother juice and sugar in a saucepan with the lid open (approx. 40 min).

Add milk and cream to the reduced juice. Warm up but do not boil. Separate eggs, add egg yolks. Heat the mass to 80-85 degrees, stirring constantly, the ice mass then thickens.

Pour the mixture through a sieve and allow to cool. Then cool down in the refrigerator and place in the ice cream maker for 60 minutes.

Beat the butter and sugar until foamy, crack open the eggs and gradually add to the foamy butter.

Chop the pistachios into medium coarse pieces, put some aside for garnish. Squeeze the lemon.

Weigh out the flour, add all the remaining ingredients to the foam mixture and stir briefly. Put the cake batter into a greased square form (24x24 cm) lined with baking paper and bake for 20 min, 170 degrees, top and bottom heat.

After cooling, cut into cubes or triangles with liquid chocolate (melt in a water bath) and decorate with whole pistachio nuts.