Step 1: Prepare the Hamburger Mixture

1. Preheat the oven to 375°F (190°C).
2. In a large skillet, heat a little oil over medium heat.
3. Add the ground beef and cook for 5-7 minutes, breaking it up as it browns.
4. Once the beef is nearly cooked, add the diced onions and minced garlic. Sauté for another 3-4 minutes until the onions soften.
5. Season with salt, pepper, smoked paprika, and Italian seasoning. Stir well.
6. Add the cauliflower rice and cook for 3-4 minutes, until it softens and most of the moisture evaporates.
7. Remove the mixture from the heat and set it aside.

Step 2: Make the Cheese Sauce

1. In a saucepan over medium heat, melt the butter and cream cheese together.
2. Add the heavy cream and stir until the mixture becomes smooth.
3. Gradually add the shredded cheddar cheese, stirring continuously until the cheese melts and the sauce thickens.
4. Season with garlic powder, salt, and pepper to taste. Remove from heat.

Step 3: Assemble the Casserole

1. In a baking dish, spread the hamburger and cauliflower rice mixture evenly.
2. Pour the cheese sauce over the top, spreading it evenly with a spoon or spatula.
3. Sprinkle a layer of extra shredded cheddar cheese on top.

Step 4: Bake the Casserole

1. Bake in the preheated oven for 15-20 minutes, until the cheese is bubbly and slightly golden on the edges.
2. Remove the dish from the oven and sprinkle grated Parmesan cheese over the top.
3. Return the casserole to the oven and bake for an additional 5 minutes until the Parmesan melts and becomes slightly crispy.

Step 5: Serve

1. Let the bake rest for 5 minutes before serving to allow the cheese to set.
2. Garnish with fresh parsley, if desired, and enjoy!