Sweet Potato Casserole

3 large sweet potatoes
3 tbsp butter, melted
1 c packed brown sugar
1 c chopped pecans
1/3 c all-purpose flour
1/2 c white sugar
2 eggs
1/4 c milk
1 tbsp gated orange zest
3 tbsp butter
1 tsp vanilla
1/2 tsp salt

Preheat oven to 350. Bake sweet poatoes for 1 hour. Cool and mash in a large bowl.
Combine softened butter with brown sugar, nuts and flour. Stir with a fork and set aside.
Combine sugar, eggs, milk, orange zest, butter, vanilla and salt with the mashed potatoes.
Beat with an electric mixture until smooth.
Pour mixture into prepared baking dish.
Sprinkle with the brown sugar nut mixture.
Bake for 35 minutes.