Preheat oven to 350 degrees. Coat a large sheet pan with cooking spray.
Cut the narrow ends off of the sweet potato, then slice each potato into 1-inch thick slices.
In a large bowl combine the maple syrup, brown sugar, melted butter, oil, salt, cinnamon, and cayenne. Toss the sweet potato discs in the mixture until coated all over. Place each sweet potato disc flat on the sheet pan, ensuring there is space between them and they do not touch. Drizzle any remaining mixture from the bowl on top.
Optional Topping: In a a small bowl add the flour, brown sugar, nutmeg, cinnamon and salt. Add the cold butter pieces and rub in with your hands or cut in with a pastry cutter until the mixture resembles coarse meal. If using, sprinkle some of the crumb topping onto the top of each sweet potato disc.
Bake the sweet potatoes for 45 - 60 minutes until they are soft and a fork comes in and out easily. (If the tops do not brown well, you can broil the topping for 5 minutes at this point).
Enjoy!