Preheat your oven to 400°F (200°C) and lightly grease a large baking dish or foil pan.
Add the sliced sausage and onions to the pan. Drizzle with olive oil and dot with butter.
Sprinkle the garlic powder, smoked paprika, salt, and black pepper over everything, then toss well to coat.
In a small bowl, mix together the barbecue sauce, honey (or brown sugar), mustard, and Worcestershire sauce.
Pour the glaze evenly over the sausage and onions, tossing gently so everything is coated.
Bake uncovered for 35–45 minutes, stirring once halfway through, until the onions are soft and caramelized and the sausage is browned.
For extra color, broil for 2–3 minutes at the end, watching closely so it doesn't burn.
Serve hot on its own or alongside mashed potatoes, rice, or crusty bread.
