Preheat oven to 425 degrees F. On a large baking sheet, season brussels sprouts, bacon, and garlic with salt and pepper. Drizzle with oil and toss until combined.Bake until brussels are tender and charred, 30 minutes.Meanwhile, make balsamic glaze: In a small saucepan, combine balsamic vinegar, honey, and rosemary. Simmer until reduced by half, stirring occasionally, 15 minutes (the mixture should coat the back of a spoon). Let cool.Drizzle roasted brussels sprouts with balsamic and serve