Pre heat oven to 400 degrees. Roast sweet potatoes on a rimmed baking sheet lined with parchment paper until fork tender- approx. 1 hour. Peel immediately and place in a large mixing bowl. While potatoes are still warm, add sugar, salt, vanilla, eggs and butter, and spices. Mix throughly until well combined and potatoes are light and fluffy- you may want to use a stand mixture for this. I just combine by hand so the mixture does not become too gluey.
Pour mixture into a well buttered two quart baking dish. You can cover and chill at this point.
Bake at 375 for 20 minutes, then add the crumble topping and bake another 15 minutes.
If potatoes have been chilled overnight, bake at 375 degrees for approximately 30 minutes. Remove from oven and sprinkle pecan topping over top of casserole. Return to oven and bake another 15 minutes or until pecans are toasted and browned.
Let rest for 20-30 minutes before serving.
