Steam the cauliflower over boiling water until fork-tender, about 15 to 20 minutes (or cook in a microwave with 2 tablespoons water for 8 to 10 minutes until very soft). Drain off any liquid. Place the cauliflower in a food processor or blender along with ½ cup broth. Puree on high until smooth. Transfer the puree to a medium saucepan.
In a cup, dissolve the cornstarch in the remaining ¼ cup broth, and add this mixture to the cauliflower puree. Add the cream cheese, Parmesan cheese, garlic powder, onion powder, and paprika. Cook over medium heat, continually stirring, until the puree begins to thicken, 2 to 3 minutes.