Spray a 2-quart baking dish with cooking spray and set aside.
Place potatoes (with the syrup from the can) in a large microwave-safe bowl. Warm in the microwave for about 30 seconds – 1 minute. Transfer to a blender or food processor to puree the potatoes until smooth.
Add the melted butter, sugar, cinnamon, nutmeg, eggs and salt to the blender and mix well.
Place potato mixture into prepared baking dish and bake, uncovered, for 20-35 minutes, or until almost set.
Meanwhile, in a bowl, combine the topping ingredients.
Spread topping onto potatoes and brown for another 8-10 minutes. Allow to rest for at least 10-15 minutes; serve warm.
Notes
COOK'S TIPS:
Do not drain the can of sweet potatoes! You want that syrup to puree with the potatoes in the blender.
I prefer salted butter in this recipe to counter-balance the sugar.
Make sure that the casserole is almost set (not liquid in the center) before you put on the topping. Otherwise, the topping might burn in the oven if you have to leave the casserole in too long.
Prep Ahead! I have prepared and baked this entire side dish in advance. Then, to reheat, cover lightly with foil and place in a 350 degree oven until heated through.