Raisins and citrus peel soaked in rum for about an hour. Sugar, yeast, a pinch of salt, milk and 5 tbsp flour mix and let it rise. Mix with remaining flour, egg yolks, 150 g butter, vanilla and lemon zest. Once thoroughly mixed add nuts, raisins and citrus peel. Mix thoroughly. In the process of mixing may be added flour, until a medium soft dough. Leave to rise. Again mixed and rolled a thick crust, approximately 20x30 cm. On one side of the cortex is folded until it covers half the dough, while the other is rolled up so as to cover the folded end. Place in a greased with butter or lard tray and bake at 170 C for about an hour - hour and a half. During this time, the remaining butter is mixed with powdered sugar glaze. After Stollen bake smeared with plenty of icing. Allow to cool before serving.