1. Place sweet potatoes in a large saucepan and cover with water. Bring to a boil. Cover and cook over medium heat until tender, 10 to 15 minutes. Drain well and return to the pan. Mash with a potato masher. Measure out 3 cups. (Reserve any extra for another use.).
2. Preheat oven to 350°F Coat an 8-inch-square (or similar 2-quart) baking dish with cooking spray.
3. Whisk eggs, oil and honey in a medium bowl. Add mashed sweet potato and mix well. Stir in milk, orange zest, vanilla and salt. Spread the mixture in the prepared baking dish.
4. To prepare topping: Mix flour, brown sugar, orange juice concentrate, oil and butter in a small bowl. Blend with a fork or your fingertips until crumbly. Stir in pecans. Sprinkle over the casserole.
5. Bake the casserole until heated through and the top is lightly browned, 35 to 45 minutes.
Makes 10 servings, about 1/2 cup each.
Per serving: 242 calories; 10 g fat (2 g sat, 5 g mono); 46 mg cholesterol; 36 g carbohydrate; 5 g protein; 4 g fiber; 170 mg sodium; 351 mg potassium.