My best friend, Chasity always makes this and it's one of my favorites. I love it with the pecan topping. However, my dad likes the marshmallows only so I did ours half and half.
Sweet Potato Casserole
3 pounds sweet potatoes peeled and chopped into 1 inch chunks
2 T butter
1/4 cup milk
1/2 t ground cinnamon
2 T brown sugar
salt to taste
Topping
4 T butter softened
1/4 cup brown sugar
1/4 cup all purpose flour
1/2 teaspoon ground cinnamon
1/8 teaspoon salt
1/2 cup chopped pecans
2 -3 cups mini marshmallows or more
Preheat oven to 375°F.
Place the sweet potatoes in a large pot, cover with water, and boil until tender (about 7 minutes, depending on the size). Drain and return to the pot. Add butter, milk, cinnamon, brown sugar and salt to the potatoes and mash until smooth. Use a hand mixer to make them extra smooth.
Place the mashed potatoes in a greased casserole dish. Place in the oven until heated through (if they're warm it will only take a few minutes).
While the sweet potatoes are heating, prepare the topping. In a medium bowl, combine butter, brown sugar, flour, cinnamon, salt, and pecans. Stir until thoroughly combined.
Remove the sweet potatoes from the oven. Top with half the marshmallows, then sprinkle half the streusel over the marshmallows. Top with the other half of the marshmallows and sprinkle the remaining streusel over the top. Place back into the oven for 8-15 minutes, until the topping is bubbly and brown (keep an eye on it so the marshmallows don't burn). You can also place it under the broiler very briefly to add a little more color to the marshmallows.
I make this a day or so prior and just finish cooking on Thanksgiving day.