Preheat the oven to 350 degrees F
Line a baking sheet with foil and brush the pan generously with cooking spray.
Break up the frozen florets and place them in a large Ziploc bag or in a bowl.
Add oil to the cauliflower and toss them together until they're evenly coated.
Add salt generously into the batch.
Sprinkle with pepper and mix everything together.
Lay the cauliflower on the baking sheet in a single layer.
Bake for 30 minutes or until they're light golden brown or soft.
Remove the cauliflower from the oven, then sprinkle with shredded cheese evenly (optional).
Return the florets to the oven and allow them to cook for an additional 3-5 minutes or until the cheese has melted.
Remove the cauliflower from the oven and garnish with parsley flakes.
Allow to cool for 5 minutes.