Prepare the Cabbage: Rinse the cabbage thoroughly under cool water and pat dry with paper towels. Cut the cabbage in half from top to root, then slice each half into 1-inch thick steaks, keeping the core intact so the leaves stay bonded together.
Season and Arrange: Place the cabbage steaks on a large baking sheet lined with parchment paper. Brush both sides evenly with olive oil, then sprinkle the garlic powder, smoked paprika, salt, and pepper over each steak, coating both sides. Lay the steaks flat on the prepared baking sheet in a single layer, leaving about 1 inch between each piece for air circulation and even browning.
Preheat Oven: Heat your oven to 425°F and allow it to reach full temperature for about 5 minutes while you finish prepping your steaks.
Roast First Side: Place the baking sheet in the preheated oven and roast for 15 minutes without moving the steaks, allowing the bottom side to develop a deep golden-brown color.
Flip and Finish: Using a thin spatula, carefully flip each cabbage steak and roast for another 12 to 15 minutes until the second side is equally caramelized and the edges appear slightly charred and crispy.
Check Tenderness: Pierce the thickest part of a steak with a fork; it should be tender but still hold its shape and not fall apart.