Sweet Potato Casserole

This is my sister's recipe and every year I am calling her to get it because I have misplaced my recipe from last year. Now I should be able to find it.

4 cups sweet potatoes
1 cup sugar
1/2 tsp. vanilla
1/2 cup melted butter
3 eggs

Topping:

1 cup brown sugar
1/2 cup flour
1 cup chopped pecans
1/2 cup melted butter

Mix first 5 ingredients throughly and put in large baking dish. Mix topping ingredients and spread on top of sweet potatoes. Bake for 30 minutes at 350 degrees.

This is more like a desert!!