Orange Pecan Topped Sweet Potato Casserole

This is a rural Texas favorite that originated in Fannin County Texas where the women really know how to cook. The recipe is attributed to "Mavin" -- someone none of us has met, but whom we've heard about. The recipe is a delicious taste of home cooking, Texas-style.
 

• 4 cups peeled, cooked, mashed sweet potatoes (about 2 ½ lbs. raw)
  
• 1/3 cup evaporated milk
  
• 1/3 cup sugar
  
• 1/3 cup plus 1 Tblsp all-purpose flour, divided
  
• 1 ½ tsp. orange zest, divided
  
• ¼ tsp. ground cinnamon
  
• 1/8 tsp. ground allspice
  
• ¼ tsp. salt, divided
  
• 2 large eggs
  
• ½ cup firmly packed dark brown sugar
  
• 1/3 cup butter, diced
  
• ¾ cup pecan, chopped
  

Preheat oven to 350°.  Spray a shallow 1 ½ quart baking dish with nonstick cooking spray.

 In a large bowl, combine sweet potatoes, milk, sugar, 1 tablespoon flour, ½ tsp. orange zest, cinnamon, allspice 1/8 tsp. salt and eggs; stir well with a whisk. Pour sweet potato mixture into prepared baking dish.In a medium bowl, combine brown sugar, remaining 1/3 cup flour, remaining 1 tsp. orange zest and remaining 1/8 tsp. salt. Using a fork, cut in butter. Stir in pecans. Sprinkle over sweet potato mixture.Bake until pecan topping is browned, about 45 minutes.