01 -
Preheat the oven to 350 degrees. Line a sheet pan with foil and coat with cooking spray. Prick the potatoes with a fork and place them on the pan.
02 -
Bake the potatoes until tender, 45 minutes to an hour.
03 -
When the potatoes are cool enough to handle, cut them open, scoop out the insides and place the potatoes in a large bowl.
04 -
Add the 4 tablespoons of butter, milk, brown sugar, maple syrup, cinnamon, egg and vanilla to the bowl.
05 -
Use a potato masher or hand mixer to mash or beat the potatoes until mostly smooth.
06 -
Grease a 9 inch square pan or 2 quart baking dish with cooking spray.
07 -
Spread the sweet potato mixture evenly in the pan.
08 -
In another bowl, mix together the brown sugar, flour, melted butter and pecans until crumbly. Sprinkle the crumb topping over the sweet potatoes.
09 -
Bake for 25-30 minutes or until topping has lightly browned.
10 -
Remove from oven, sprinkle the marshmallows over the top then return to the oven.
11 -
Bake for an additional 3-5 minutes or until marshmallows are just melted.
12 -
Serve immediately.