Dissolve the yeast in 100ml of the warm water and 1 tablespoon sugar. Mix together and allow to foam for 5 minutes. Meanwhile, place the classic bread mix, salt, ground hazelnuts, spices into the bowl of a food processor. Add in the foamed yeast mixture, followed by the remaining warm water and whizz to a smooth dough. It is important to allow the mixture to knead in the processor for at least 1 minute. Place the dough in a clean bowl, cover with cling film and leave in a warm place until it has doubled in size. When ready, remove from the bowl and open out into a large rectangle. Brush with half of the melted butter and evenly sprinkle over the sugar and chopped nuts. Roll up tightly like a Swiss roll and join the 2 ends together into a ring. Place on a baking tray covered with non-stick baking paper and brush with the remaining melted butter. Allow to rise again for at least 30 minutes. Next, place into the oven and bake for approximately 30-40 minutes at 200° C, or until cooked through. Remove from the oven and immediately prepare the glace icing topping. With the icing sugar with a little water to create a soft icing and brush all over the nut ring. Sprinkle over some extra cinnamon and decorate the top with walnut halves. Can be served whilst still warm or at room temperature.