Preheat the oven to 350 degrees. Spray a 2 quart baking dish with nonstick cooking spray.
Cook the frozen cauliflower in boiling salted water 10 minutes, drain well. Mash with a potato masher gently for just a few seconds, leaving some chunks of cauliflower.
Add the salt, pepper, Cajun seasoning, onion powder, butter, cream cheese, parsley and 1 cup of the shredded cheese; mix well. Spoon into the prepared baking dish. Sprinkle with paprika and then the remaining 1/2 cup cheese.
Bake 20-25 minutes, or until bubbly and light brown on top.