Preheat your oven to 425°F (220°C). Line a large baking sheet with parchment paper for easy cleanup.
In a large bowl, combine the cauliflower florets with olive oil, garlic powder, onion powder, smoked paprika, salt, and black pepper. Toss until the cauliflower is evenly coated.
Spread the cauliflower in a single layer on the prepared baking sheet.
Roast in the preheated oven for 20 minutes.
Remove the baking sheet from the oven and sprinkle the grated Parmesan cheese evenly over the cauliflower.
Return the baking sheet to the oven and roast for an additional 10-15 minutes, or until the cauliflower is golden brown and crispy.
Once done, remove from the oven and let cool for a few minutes. Garnish with chopped parsley if desired before serving.