My Family's Ultimate Sweet Potato Candied Yams - Chef YoYo

Ingredients

• 4 medium sweet potatoes (about 2 pounds or 900 grams)
• 1/2 cup (100 grams) packed brown sugar
• 1/4 cup (60 ml) unsalted butter
• 1 teaspoon vanilla extract
• 1/2 teaspoon ground cinnamon
• 1/4 teaspoon ground nutmeg
• 1/4 teaspoon salt
• 1 cup (240 ml) water
• Chopped pecans or walnuts for topping
• Marshmallows (optional)