Orange Creamsicle

In a saucepan, cook sweet potatoes in boiling salted water until tender. Drain and allow to cool to room temperature. Peel and mash or puree until smooth. In medium saucepan, combine orange juice, water, sugar and cinnamon sticks. Bring to boil; reduce heat to medium and cook until mixture coats the back of a spoon, about 7 minutes. Remove from heat. Remove and discard cinnamon sticks. In large saucepan, gradually blend syrup into mashed sweet potatoes. Cook over medium heat, stirring until mixture pulls away from the sides of the pan. Blend 1/2 cup mixture into egg yolks; blend into mixture in saucepan. Add remaining ingredients. Cook, stirring for 5 minutes. Spoon into serving dishes. Chill until ready to serve. If desired, garnish with non-dairy whipped topping or whipped cream and toasted almonds and mint leaves.