Vegetable-oil cooking spray
5 pounds sweet potatoes
1/2 cup fresh orange juice
1/2 teaspoon fresh-grated orange zest
3 large eggs, lightly beaten
1/2 cup granulated sugar
1 1/2 teaspoons baking powder
1 1/2 teaspoons vanilla extract
2 Tablespoons butter
2 cups chopped pecans
1 cup light or dark brown sugar, (firmly packed)
1/2 cup butter
1 teaspoon vanilla
1/8 teaspoon salt
Lightly coat a 9- by 13-inch pan with cooking spray and set it aside.
Preheat oven to 350ºF.
With a fork, prick sweet potato skins all over and roast on a baking sheet until soft, about 1 hour.
Allow sweet potatoes to cool, then peel.
Place in a large bowl and mash until smooth with a potato masher.
Add orange juice and zest.
Fold in eggs, granulated sugar, baking powder, vanilla, and butter.
Pour the sweet potato mixture into the prepared pan.
(At this point the casserole can be tightly covered and refrigerated until ready to serve.)
Make praline streusel:
In a saucepan, place pecans, brown sugar, butter, vanilla, and salt and bring to a boil.
Cook 2 minutes, then pour over sweet potato mixture.
Bake until bubbly and brown, 40 to 45 minutes.