In a large mixing bowl, combine 2 cups ricotta cheese, 1 cup chopped fresh spinach, 1/2 cup grated Parmesan cheese, 1/2 cup shredded mozzarella cheese (reserve remaining 1/2 cup for topping), 1 egg, 1 teaspoon garlic powder, 1 teaspoon onion powder, and salt and pepper to taste. Mix thoroughly until creamy and well incorporated.