In a large mixing bowl, combine 2 cups ricotta cheese, 2 cups chopped fresh spinach, 1 cup shredded mozzarella, 1/2 cup grated Parmesan, 1 egg, 1 teaspoon garlic powder, 1 teaspoon onion powder, and salt and pepper to taste. Mix well until all ingredients are evenly incorporated. The egg helps bind the filling so it stays inside the rolls during baking.