Preheat your oven to 400 degrees
Peel and slice the sweet potatoes into quarter inch slices
Combine 8 tablespoons of melted butter with 1/3 cup of maple syrup, 1/2 cup of brown sugar, 1 teaspoon of vanilla extract, 1 teaspoon of ground cinnamon, 1/2 teaspoon of ground ginger, 1/2 teaspoon of cloves, 1/4 teaspoon of cardamom, 1/4 teaspoon of salt and 1/4 teaspoon of black pepper in a large bowl
Squeeze the juice from a fresh orange or clementine into the sauce (about 2 tablespoons of juice) and whisk until the sauce is combined
Add the sliced sweet potatoes and carefully mix until every slice is coated in sauce
Arrange the sweet potato slices in a greased 3 quart baking dishÂ
Cover the dish tightly with tin foil
Bake in a 400 degree oven for 30 minutes
Carefully remove the foil and brush the sweet potatoes with the remaining sauce
Bake uncovered for an additional 20-30 minutes or until the sweet potatoes are very tender
Transfer the baking dish onto a heat proof surface and allow the syrup to thicken for a few minutes
Garnish as desired and serve warm