To make the dough, put the flour, 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. Place the dough onto a floured surface and knead well for 4 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, then spread over the chocolate spread. Sprinkle over the sugar, pecans, chopped chocolate and cinnamon. Roll up tight from top to bottom, into a large Swiss roll and cut in half all the way down the middle of the roll. Twist the 2 pieces together and form into a ring, pinching the 2 ends together. Brush a large baking tray with some of the remaining butter, and place on the ring and 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 the icing sugar with a little warm water to make a glace icing. As soon as the wreath comes out of the oven, brush all over with the icing to glaze and finish off with a generous sprinkling cinnamon and chopped chocolate.