Preheat the oven to 400°F (200°C) and prepare a baking sheet.

Remove the outer leaves from the cabbage and slice into ¾-inch thick rounds.

In a bowl, combine olive oil, garlic powder, smoked paprika, onion powder, thyme, salt, and black pepper.

Brush the seasoning mixture onto both sides of each cabbage steak.

Arrange the seasoned cabbage steaks on the baking sheet in a single layer.

Roast in the oven for 25–30 minutes, flipping halfway through.

Serve hot, topped with Parmesan cheese, red pepper flakes, or parsley if desired.