To make the dough, put the gluten-free bread mix, salt, sugar and butter in a large bowl and rub together till the mixture resembles breadcrumbs. Add in the zest, yeast and warm milk and mix to a soft dough (you can alternatively use a food mixer or processor) Place the dough onto a floured surface and knead well for 5 minutes. Put the dough into a floured bowl, cover with plastic and leave to rise till double in size, for about an hour. Knock back the dough and roll out to a large square, 40cm x 25cm. Brush the dough with half of the melted butter, sprinkle over the cinnamon, dried fruits and nuts. Roll up tight from top to bottom, into a large Swiss roll and cut up into 12 equal slices, but only half way through so that it is all still intact. Join the ends together to form a ring. Brush a large baking tray with some of the remaining butter and carefully place on the bread ring. Brush with the remaining butter. Cover with plastic and leave to rise again till double in size again. Bake in the oven for 35-40 minutes at 210`c, till golden brown. Meanwhile, mix 5 tablespoons icing sugar and 1 teaspoon cinnamon with a little warm water to make a glace icing. Brush the cinnamon icing quickly all over the bread ring Finally, finish off with a generous sprinkling of the extra cinnamon and chopped nuts. Serve whilst still warm.