Preheat oven to 425 degrees.
Brush sheet pan with sides with olive oil.
Prepare cauliflower by washing and drying with a paper towel. Cut cauliflower into quarters. Pull or cut off the stem leaf portion at the base of the cauliflower. Separate the cauliflower into flowerets and then cut the cauliflower into edible sized pieces so each piece has at least one flat side. Cut the pieces the same size if possible so they all cook evenly.
Place the cauliflower flat side down on the pan. Leave some space between each piece so they will roast evenly and carmelize.
Drizzle olive oil over the cauliflower so each piece has some olive oil on it.
Grind fresh pepper and sprinkle salt and garlic powder or garlic salt over the cauliflower to taste. Lightly sprinkle with paprika (optional).
Roast the cauliflower for about 25-35 minutes (it may take longer if your cauliflower pieces are thicker). After the first 15 minutes turn with tongs or stir the cauliflower so the browned sides are facing up. Roast for another 15 minutes or until the cauliflower is a nice golden brown color. During the last 2-3 minutes sprinkle the parmesan cheese over the top and let it melt over the cauliflower.
Sprinkle fresh chopped parsley or dried parsley over cauliflower for garnish
Any extra cauliflower can be roasted in a separate pan. You can bake them at the same time and rotate the pans in the oven or roast separately (my preference).