Heat oven to 400°F. Spray 2-quart gratin dish or 3-quart casserole with cooking spray.
Arrange half of the sweet potatoes overlapping in dish. Sprinkle with 1/4 cup of each cheese; repeat layers. In small bowl, mix whipping cream, salt and red pepper. Pour mixture over potatoes.
Cover dish with foil; bake 20 minutes. Remove foil; bake uncovered 25 minutes longer or until potatoes are tender and top is browned. Sprinkle with bacon. Let the gratin stand 15 minutes before slicing.