Preheat oven to 400 convection bake. Peel and wash your sweet potatoes. Cut the whole potato into 1 1/2 inch pieces. Place each piece cut side down in a standard baking dish. Tip: for easy cleanup, use a disposable foil pan. You can buy 1/2 pans cheap at a big box club store.
Melt the butter (I melt the butter in the microwave for 30 sec.) While butter is hot mix in brown sugar. Once brown sugar is dissolved, pour mixture over the sweet potatoes and completely coat each piece by rolling them around in the mixture.
Cover dish with foil and convection bake 400 for 45 minutes.
Remove foil and sprinkle the top of each piece with the cinnamon and cinnamon sugar. DO NOT TAKE A SHORTCUT AND USE JUST CINNAMON SUGAR. The pure cinnamon makes the dish.
Cook uncovered 400 convection bake for 15 minutes or until brown on top. Remove from oven and drizzle the juice in the pan over the sweet potatoes.