Make syrup by combining sugar, water and lemon juice. Pare pears, remove core. Place in an ungreased, 2-quart casserole. Pour syrup over pears. Bake covered at 350° F (180° C) until tender 45 to 60 minutes. Meanwhile make raspberry sauce. Drain juice and rub berries through a fine sieve, pressing with a wooden spoon to get all of puree. To make chocolate curls, have bar at room temperature, and use a potato peeler. Refrigerate. To serve pears, cool 30 minutes after baking. Pour hot raspberry sauce over pears. Garnish with chocolate curls.