Brown the beef:
Preheat your oven to 375°F (190°C). In a large skillet over medium-high heat, cook the ground beef, breaking it apart with a spoon. Season with salt, pepper, onion powder, and paprika. Cook for 6–8 minutes until fully browned and no pink remains. Drain excess fat and set aside.

Prepare garlic butter rice:
In a large saucepan, melt the butter over medium heat. Add minced garlic and sauté for 1–2 minutes until fragrant. Stir in the cooked rice, beef broth, and heavy cream. Mix well and simmer for 3–4 minutes until the liquid is mostly absorbed and the rice becomes creamy.

Layer the casserole:
Grease a 9×13-inch baking dish with butter or cooking spray. Spread the creamy garlic butter rice evenly across the bottom. Layer the cooked ground beef over the rice. Sprinkle shredded cheddar cheese over the beef, followed by the mozzarella cheese on top.

Bake:
Place the dish in the oven and bake for 25–30 minutes, until the cheese is melted, bubbly, and lightly golden. For extra browning, broil for 2–3 minutes, watching carefully.

Garnish and serve:
Remove from the oven and let the casserole rest for 5 minutes. Sprinkle freshly chopped parsley over the top and serve hot, scooping through all layers for the perfect bite.