Preheat your oven to 375°F (190°C) and position a rack in the center.
Peel the sweet potatoes and cut them into 1-inch cubes.
In a large mixing bowl, combine the melted butter, brown sugar, pure maple syrup, ground cinnamon, ground nutmeg, salt, and black pepper. Stir until all the ingredients are well incorporated.
Grease a 9x13-inch (23x33 cm) baking dish with cooking spray to prevent sticking.
Place the cubed sweet potatoes in the greased baking dish.
Pour the glaze over the sweet potatoes. Using a spatula, gently toss to coat all the pieces evenly.
Cover the baking dish with aluminum foil and place it in the preheated oven.
Bake for 20 minutes with the foil on to allow the sweet potatoes to steam and become tender.
After 20 minutes, remove the foil and continue baking for an additional 15-20 minutes or until the sweet potatoes are tender and the glaze has thickened.
Once the oven candied sweet potatoes are done, remove them from the oven and let them rest for a few minutes to allow the glaze to set.
Serve your candied sweet potatoes hot and enjoy.