First, start your filling. Finely chop the dried pear or apple and mix in a bowl with your chosen liqueur or water. Set aside.
For the dough, melt the butter with the milk in a pan over a low heat. Stir in the saffron, set aside and allow to cool.
Mix the sugar, ½ a teaspoon of sea salt, yeast and flour in the bowl of a free-standing mixer. Gradually add the milk mixture and mix well.
Using the dough hook attachment on the mixer, knead for 15 minutes, or until silky and coming away from the sides of the bowl. Place in a greased bowl, cover and leave to rise for 1 hour, or until doubled in size.
Returning to the filling, drain the dried fruit and add to a bowl. Finely grate in the lemon zest, finely chop the hazelnuts and add along with rest of the filling ingredients, rubbing together with your fingers. Cover and set aside.
Preheat the oven to 180ºC/350ºF/gas 4.
Roll out the dough on a floured surface into a 28cm x 70cm rectangle. Spread the filling over the dough, leaving a 3cm border all the way around.
Roll the dough up from one of the longer ends, pressing the edge firmly to seal. Cut the roll in half lengthways, turn the pieces cut-side-up, then loosely twist around each other.
Bring the ends together into a ring, tuck one under the other, and press to seal. Transfer the wreath to a baking tray, cover with a clean tea towel and set aside for 30 minutes, or until increased by half its size.
Bake in the middle of the oven for 30 to 35 minutes, or until golden and the bottom sounds hollow when tapped. Allow to cool on a rack.
Meanwhile, whisk the icing sugar, cardamom 1 tablespoon of lemon juice and 2 tablespoons of water in a bowl. Drizzle over the wreath, and serve.