Do not preheat oven. Grease a tube pan. Pour ½ cup of the pecans in the bottom of the pan.
Mix together cake mix, pudding mix, eggs, ½ cup blackberry wine, oil, and water. Pour the cake batter over pecans in pan. Top with the remaining ½ cup pecans.
Place in cold oven. Turn on oven and set temperature to 300 degrees. Bake for one hour.
Place sugar, the remaining ½ cup blackberry wine, and margarine in a saucepan. Cook on stove for 5 minutes. Pour topping over hot cake and let the cake stand for one hour.