Preheat the oven to 400 degrees F.
Place the broccoli florets in a large bowl. Spray the florets once with the canola oil cooking spray. Toss the florets and spray again with the cooking spray. Add the pepper flakes and garlic and stir until well distributed. Pour the broccoli mixture into a casserole dish and top with the cheese. Transfer to the oven and roast for 15 minutes. Serve warm.