Preheat the oven to 400 degrees. Spray a metal 13X9 inch pan with cooking spray. Toss the Cauliflower with 2 tablespoons of the melted butter and spread out in the prepared pan, season with salt and pepper. Place the pan in the oven and roast about 20 minutes, turning the florets once. They should lightly browned in spots.

In a small bowl, whisk together the broth, remaining butter, grated garlic and about half the rosemary. Carefully pour it over the cauliflower and return the pan to the oven. roast for another 10 minutes or so until the liquid is reduced by half.

Remove from the oven and sprinkle with the parmesan and gently mix. Transfer to a serving bowl and sprinkle with the remaining rosemary and the red pepper flakes. Serve hot.