Rinse off the sweet potatoes and remove any dirt. Pour a generous amount of water in a large pot and put on high heat on the stove. Add the sweet potatoes (full--do not cut) and bring the water to a boil.
Let the potatoes boil until you can poke the center with a knife and it is soft. When they are soft, drain the water completely and let them sit in a colander for a while until you can peel them. Some water will drain out which will be good.
Peel the sweet potato skin from the potato and place the flesh into a large mixing bowl or mixer. Mix the potatoes until they are totally soft. Add the sweet potato mixture ingredients and whip until fluffy and soft.
Spray a 9x13 pan with cooking spray and pour the sweet potato mixture into the dish.
Make the crust by adding all of the ingredients into a food processor and pulse until combined. You can also chop the nuts by hand if you don't have a processor.
Sprinkle the crust mixture evenly over the surface of the sweet potatoes.
Bake for 30 minutes at 350. Allow the casserole to sit 20-30 minutes before serving.
Notes
The topping to this casserole is what makes it over the top amazing!