* 14 cups ( 1-inch) cubed peeled sweet potato (about 5 pounds).
* 1/2 cup half-and-half
* 1/2 cup maple syrup
* 1 tsp vanilla extract
* 3/4 tsp salt
* 1 large egg, lightly beaten
* Cooking spray
* 1/2 cup-all-purpose flour
* 1/2 cup packed brown sugar
* 1/4 cup chilled butter, cut into small pieces
* 1/2 cup chopped pecans
1. Preheat oven to 375 degrees F.
2. Place potato in a Dutch oven , and cover with water. Bring to a boil. Reduce heat, simmer 12 minutes or until tender. Drain.
3. Combine the half-and-half and next 4 ingredients in a large bowl, stirring with a whisk. Add potato to egg mixture,; beat with a mixer at medium speed until smooth.
4. Spoon potato mixture into a 13 x 9-inch baking dish coated with cooking spray. Combine flour and sugar in a food processor, pulse to combine. Add chilled butter; pulse until mixture resembles coarse meal. Stir in pecans; sprinkle over potato mixture.
5. Cover and bake at 375 degrees F for 15 minutes. Uncover and bake an additional 25 minutes or until the topping is browned and the potatoes are thoroughly heated.