Poke the sweet potato all over with a fork and put in the microwave on a paper towel on HIGH for 8 minutes or until completely cooked through. Let rest for 5 minutes. Peel the outside and dice into 1/2" cubes. Set aside.
Preheat the oven to 350°F. Dice the bread into 1" cubes. Place on a baking sheet and bake for 20 minutes, stirring once. Remove and set aside.
Add olive oil to skillet over medium heat. Add chicken sausage and stir and crumble until fully cooked. Set aside.
In a medium sized bowl, combine milk and following 4 ingredients. Mix well. Set aside.
In a large bowl, combine bread, sweet potato, half the sausage and half the cheese. Pour milk and egg mixture over bread mixture and let sit for 20 minutes.
Spoon the soaked bread mixture into an 8x8 pan sprayed with non-stick cooking spray.
Top with the remaining sausage and cheese.
Cover with foil sprayed with cooking spray to keep it from sticking to the top.
(OPTIONAL MAKE-AHEAD) If making the night before, place in the refrigerator at this point.
Bake at 350° for 30 minutes. Remove foil and bake for an additional 20 minutes or until fully cooked.
Slice and serve with syrup drizzled on top!