In a nonreactive medium saucepan, combine the sugar, vinegar, ginger, cayenne, ras al hanout and salt and bring to a boil over moderate heat. Add the pears, cover and cook until they are crisp-tender, about 10 minutes. Strain and transfer the pears to a bowl. Return the liquid to the pan and boil over moderately high heat until reduced to 1/2 cup, about 5 minutes. Stir in the pears and let cool. Serve chilled or at room temperature.