Trim and halve the 2 pounds Brussels sprouts, removing any outer leaves that are wilted or damaged.
In a large bowl, toss the Brussels sprouts with 4 tablespoons vegetable oil, 6 tablespoons melted butter, 2 tablespoons Demerara sugar, Salt and freshly ground black pepper. Make sure they are evenly coated.
Preheat your air fryer to 375°F (190°C). Place the Brussels sprouts in a single layer in the air fryer basket, making sure they are not overcrowded. Cook for 15-20 minutes, shaking the basket halfway through for even cooking. The sprouts should be golden brown and crispy on the edges.
While the Brussels sprouts are cooking, cook the 5 pieces bacon until crispy and chop it into small pieces.
Once the Brussels sprouts are done, transfer them to a serving dish. Drizzle with 15- year aged balsamic vinegar or balsamic glaze, and sprinkle the chopped crispy bacon over the top.
Serve immediately and enjoy your delicious, caramelized Brussels sprouts with a perfect crispy texture and savory-sweet flavor!