Preheat oven to 400°F (205°C)
Peel and cut 2 to 3 pounds of yams or sweet potatoes into 1-inch chunks
Place yams in a large pot and cover with water
Boil 10 to 15 minutes, until just tender
Drain and set aside
In a bowl, mix: 1 cup brown sugar, 1/2 cup melted butter, 1/4 cup orange juice (or water), 1 teaspoon vanilla, 1/2 teaspoon cinnamon, 1/4 teaspoon nutmeg, and 1/4 teaspoon salt
Transfer yams to a baking dish
Pour the sauce over the yams and toss to coat
Cover with foil and bake 20 minutes
Uncover and bake 15 to 25 minutes, until caramelized and bubbling
Optional: broil 1 to 3 minutes for extra browning
Rest 5 to 10 minutes before serving