Ruth Chris' Sweet Potato Casserole

 Topping

1 C brown sugar

1/3 C all-purpose flour

1 C pecans, chopped

1/3 C butter

Sweet Potato Mixture

3 C mashed sweet potatoes

1 C white sugar

1/2 tsp salt

1 tsp vanilla

2 eggs, beaten

1/2 C butter, melted

Bake sweet potato mixture in 9x13" casserole dish for 25 min.  Sprinkle topping over top and back another 10-20 minutes.