Preheat oven to 350 degrees.
Pierce potatoes several times all over with a fork and place on a baking sheet.
Bake potatoes until tender, about 60 minutes.
Once cool enough to handle, peel potatoes and add to a large mixing bowl.
Whip potatoes with an electric mixer until fluffy and smooth. You need about 4 cups of whipped sweet potatoes.
Add sugar, eggs, butter, evaporated milk, vanilla, cinnamon, salt, and nutmeg to the potatoes.
Mix with electric mixer and put in a greased square casserole dish.
Add topping ingredients to a bowl and mix well. Spread on top of potatoes.
Bake for 30-35 minutes until heated through.