1ST STEP:

3 c. cooked, mashed sweet potatoes (can use canned yams, mashed)
1 c. sugar
1 stick butter, softened
1 tbsp. vanilla
2 eggs, slightly beaten

Mix all together. Set aside.

2ND STEP:

1 1/2 c. light brown sugar
1/2 c. flour
1 stick butter
1 1/4 c. nuts, crumbled walnuts

Mix all together by hand with fork. Set aside. Place in a greased baking dish the sweet potato mixture. Then crumble topping over it. Bake at 350 degrees for 1 hour.