Preheat oven to 375℉ and lightly grease an 8” gratin dish.
In a medium skillet heat oil over medium. Cook bacon in oil until crisp. Set aside to cool.
Place Brussels sprouts in baking dish. In a medium bowl whisk together half-and-half, flour, salt, and pepper. Crumble or chop bacon, stir into half-and-half mixture, and pour over Brussels sprouts. Sprinkle with Parmesan Cheese and breadcrumbs.