Sweet Potato Casserole

3 lbs sweet potatoes, peeled and cut into cubes
1/2 cup brown sugar
1/3 cup butter, softened
1/2 t vanilla extract
3/4 cup chopped pecans, divided
1/4 t cinnamon
salt and pepper
2 cups mini marshmallows

Preheat oven to 375 degrees. Grease a 9x13 pan.
Place sweet potatoes in a pot of boiling water. Simmer for 15 minutes or until fork tender. Drain.
Mash the sweet potatoes, with butter, sugar, vanilla, cinnamon, salt and pepper.
Fold in half of the pecans, and spread into prepared pan.
Sprinkle with marshmallows, and the remaining pecans.
Bake for 25 minutes or until marshmallows are golden brown, and potatoes are heated through.