Preheat the oven to 400°F.
Remove the leaves from the cauliflower head and trim the stem.
Set the cauliflower upright on a cutting board and slice it into 1-inch-thick steaks. You should be able to get 2 to 4 steaks out of one head of cauliflower.
Place the cauliflower steaks on a large baking sheet lined with parchment paper.
In a small bowl, mix together the olive oil, garlic powder, smoked paprika, salt, and black pepper.
Brush the cauliflower steaks with the oil mixture, making sure to coat both sides.
Roast the cauliflower for 25 minutes or until it is tender and caramelized.
Remove the cauliflower steaks from the oven and serve immediately.