Preheat your oven: Set your oven to 375°F (190°C).
Peel and slice yams: Peel the yams and cut them into evenly sized rounds or wedges.
Create the candied coating: In a saucepan over medium heat, combine the maple syrup, Tahitian vanilla extract, unsalted butter, brown sugar, salt, cinnamon, and nutmeg. Stir continuously until the mixture becomes a smooth, slightly thickened syrup.
Layer the yams: Place the yam slices in a greased baking dish. Pour the syrup mixture over the yams, ensuring that each piece is well coated.
Bake: Cover the baking dish with aluminum foil and bake for 45 to 50 minutes, or until the yams are tender. Halfway through the baking time, remove the foil to allow the yams to caramelize.
Garnish and serve: If using pecans, sprinkle them over the yams for added texture and flavor. Serve warm and enjoy!