Cheese Stuffed Manicotti

Name: Cheese Stuffed Manicotti
Ingredients: 1 ( 8 - ounce ) box dried manicotti shells (about 12); 1 3/4 pounds whole or skim milk ricotta (3 1/2 cups); 2 large egg yolks; 8 ounces (2 cups) shredded mozzarella , divided; 2/3 cup finely grated Parmesan; 1 teaspoon finely grated lemon zest; 1/4 cup chopped fresh parsley , plus more for garnish; 1/4 teaspoon kosher salt , or more, to taste; 1/8 teaspoon freshly ground black pepper; Pinch ground or grated nutmeg; 1 ( 25 - ounce ) jar store-bought marinara sauce , or 2 1/2 cups homemade marinara , divided