Boil sweet potatoes in cold water, just covering, until fork tender. Drain well.
Process into a puree in a food processor, immersion blender or in a ricer.
While the potatoes are still warm add the butter, stirring until it melts. Then add the maple syrup, eggs, vanilla and salt.
Pour into a 1 ½ - 2 quart casserole dish.
Mix all the topping ingredients together in a medium bowl and sprinkle over the top.
Bake 30-40 minutes until bubbling.
Notes
I did like this casserole better when it was prepared right before baking, but an overnight stay in the refrigerator wasn’t the end of the world. IF you do want to make it in advance (and I feel that), then make the filling, put it in the dish and keep it covered in the refrigerator until the day of. Add the topping then bake. This will keep the topping crisp. You could also make the whole thing ahead and the refresh it in the oven before serving. I halved this recipe for the dish that you see in the photos and in the videoServes 8-10