Step 1

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.

Step 2

Bake the potatoes until tender, 45 minutes to an hour.

Step 3

When the potatoes are cool enough to handle, cut them open, scoop out the insides and place the potatoes in a large bowl.

Step 4

Add the 4 tablespoons of butter, milk, brown sugar, maple syrup, cinnamon, egg and vanilla to the bowl.

Step 5

Use a potato masher or hand mixer to mash or beat the potatoes until mostly smooth.

Step 6

Grease a 9 inch square pan or 2 quart baking dish with cooking spray.

Step 7

Spread the sweet potato mixture evenly in the pan.

Step 8

In another bowl, mix together the brown sugar, flour, melted butter and pecans until crumbly. Sprinkle the crumb topping over the sweet potatoes.

Step 9

Bake for 25-30 minutes or until topping has lightly browned.

Step 10

Remove from oven, sprinkle the marshmallows over the top then return to the oven.

Step 11

Bake for an additional 3-5 or until marshmallows are just melted.

Step 12

Serve immediately.