Preheat the oven to 375°F (190°C).
Steam or boil cauliflower florets until tender, about 5 to 7 minutes, then drain.
In a large mixing bowl, combine heavy cream, cream cheese, minced garlic, onion powder, salt, pepper, and paprika; mix until smooth.
Stir in shredded cheddar cheese and half of the Parmesan cheese.
Add the cauliflower and mix until evenly coated with the cheese mixture.
Transfer the mixture to the greased baking dish and sprinkle with remaining Parmesan cheese.
Bake for 25 to 30 minutes until bubbly and golden on top.
Garnish with fresh parsley before serving.