Preheat oven to 350 F. Cut the ends off of the brussels sprouts and place them into a large saucepan. Cover with water and bring to a boil over medium heat. Let cook for about 5-10 minutes, until tender.
Drain and place brussels sprouts into a round baking dish. In a medium saucepan over medium heat, melt butter. Cook minced garlic until fragrant. Add in flour and cook for a minute to brown.
Add in heavy cream, grated parmesan cheese, salt and pepper. Let cook while whisking constantly, until the sauce has thickened.
Mix sauce with brussels sprouts in the baking dish. Top with shredded mozzarella cheese and sprinkle with bacon bits. Bake for 40-50 minutes.