Sweet Potato Casserole

Bahan-bahan (16 porsi)

• 3 pounds sweet potatoes (peeled and cut into cubes)
• ½ cup brown sugar (packed)
• ⅓ cup butter (softened)
• ½ teaspoon vanilla extract
• ¾ cup chopped pecans (divided)
• ¼ teaspoon cinnamon (or to taste)
• salt and black pepper (to taste)
• 2 cups miniature marshmallows