Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
Remove any loose outer leaves from the cabbage. Slice the cabbage into thick wedges (about 1–1.5 inches wide). Keep the core intact so the wedges hold together.
Place the wedges on the baking sheet. Drizzle with olive oil and rub gently to coat.
Sprinkle garlic powder, smoked paprika (if using), salt, and black pepper over the wedges.
Roast in the oven for 25–30 minutes. Flip the wedges halfway through. They should have slightly crispy edges and tender centers.
While the cabbage is roasting, mix Dijon mustard with apple cider vinegar or lemon juice to make a light sauce.
Once the cabbage is done, drizzle the sauce over the wedges. Sprinkle with optional toppings if desired.
Serve immediately and enjoy!