3 c. cooked sweet potatoes, or 1 lg. can yams, drained
1/2 c. sugar
1 tbsp. vanilla
1/2 c. milk
1/4 c. butter
2 eggs

Mash potatoes in large bowl with all remaining ingredients. Mix well. Pour into a 9 x 13 inch lightly greased pan.

TOPPING:

1/2 c. flour
3/4 c. brown sugar
1/2 c. butter
1 1/2 c. chopped walnuts

Mix flour and brown sugar. Cut in butter. Add walnuts. Pat on top of casserole and bake at 325 degrees for 1 hour.