Spray a 3 quart baking dish with nonstick vegetable spray or lightly butter it. Arrange the sliced sweet potatoes in the dish in an even layer. In a large bowl, whisk together the Maple Cream ingredients until well combined. Pour the mixture over the sweet potatoes, and push them down a bit to be sure they are coated in liquid.
In a small bowl, combine the Topping ingredients and set aside.
Bake the potatoes for 35 minutes, and then sprinkle them with the topping. Bake for another 25 to 35 minutes, or until the topping is browned, the potatoes are tender, and the liquid is thickened.
Garnish with a sprinkle of fresh sage leaves if desired.