To begin, set your oven temperature to 425 degrees Fahrenheit (220 degrees Celsius). Place a layer of aluminum foil on a baking sheet for easy cleanup.
Combine cauliflower and oil in a bowl. Arrange the cauliflower evenly on the baking sheet that has been prepared, ensuring it is in a single layer.
Cook the cauliflower by stirring it occasionally until it becomes tender and starts to brown slightly, which should take around 30 minutes. It is important not to overcook the cauliflower as it can become bitter. Set aside 1/2 cup of cauliflower florets for garnishing purposes and keep them warm. Allow the rest of the cauliflower to cool down slightly.
Blend together cooled roasted cauliflower, 1 1/3 cups of broth, salt, pepper, and garlic powder in a blender or food processor, making sure to work in batches if necessary. Ensure the mixture is smooth by blending thoroughly and adding additional broth as needed until the desired consistency is achieved.
Take the mixture and transfer it to a saucepan. Heat it over medium heat until it reaches a boiling point. Once boiled, remove it from the heat and stir in the cream and 2 tablespoons of cheese until melted. Serve the dish with the cauliflower florets that were set aside, the remaining cheese, parsley, and optionally, additional pepper.