Boil sweet potatoes until tender. Then peel off skins.
Whip in mixer until fluffy.
Add vanilla, butter, and eggs.
Pour into greased casserole dish.
Meanwhile, combine all dry crumb topping ingredients in a bowl and mix well.
Pour melted butter over top. Mixture should be dark and clumpy.
Sprinkle crumb topping generously over sweet potatoes.
Bake at 350 for 45-55 minutes.