Customize quantities based on your desired number of servings. – 16-20 jumbo pasta shell – 2 cups ricotta cheese – 1 cup shredded mozzarella cheese – 1/2 cup grated Parmesan cheese – 1 large egg – 2 tablespoons fresh parsley, chopped – 1 teaspoon garlic powder – Salt and pepper to taste – 2 cups marinara sauce – Extra shredded mozzarella and Parmesan cheese for topping – Fresh basil leaves for garnish (optional)