Preheat oven to 350 degrees F.
Steam the sweet potato slices in a steamer.
As the sweet potatoes are steaming, add butter to a microwave safe bowl.
Add maple syrup, cinnamon and brown sugar. Microwave on high for 20-25 seconds. Mix thoroughly and set aside.
Add the sweet potato slices to a large square baking dish overlapping the potatoes in rows.
Then pour the syrup mixture evenly over the sweet potatoes.
Bake uncovered for 30-35 minutes.
