Preheat oven to 375°F (190°C).
Melt butter in a pan over medium heat, then add shrimp and scallops. Cook for 2-3 minutes until slightly opaque.
In a bowl, mix cooked seafood with crab meat, cooked rice, cheddar cheese, heavy cream, garlic powder, onion powder, salt, and pepper.
Transfer mixture to a greased baking dish and top with Parmesan cheese and breadcrumbs.
Bake for 20 minutes or until golden brown.
Garnish with fresh parsley before serving.