Prepare the cauliflower: Bring a large pot of salted water to a boil. Add the cauliflower florets and cook for about 5-7 minutes, or until tender. Drain and set aside.
Make the cheese sauce: In a medium saucepan, melt the butter over medium heat. Add the heavy cream and bring to a simmer. Stir in the cream cheese, cheddar cheese, and Parmesan, whisking until smooth and creamy. Season with garlic powder, onion powder, salt, and pepper.
Combine cauliflower and cheese sauce: Add the cooked cauliflower to the cheese sauce and stir gently to coat the cauliflower in the sauce. Taste and adjust seasoning as necessary.
Optional topping: If you like a crispy topping, preheat the broiler. Transfer the cauliflower and cheese mixture to a baking dish and sprinkle with breadcrumbs. Place under the broiler for 2-3 minutes, or until golden brown and crispy.
Serve: Garnish with fresh parsley if desired and serve hot! Enjoy your creamy, comforting homemade cauliflower “mac & cheese.”