Baked Pasta with Meatballs and Spinach

Heat broiler. Line a rimmed baking sheet with nonstick foil. Cook the pasta according to package directions. Drain the pasta and return it to the pot. Meanwhile, chop 1 cup spinach. In a large bowl, whisk together the egg, 2 tablespoons of water, and 1/2 teaspoon each of salt and pepper. Stir in the garlic and parsley, then the bread crumbs and Parmesan. Let sit for 2 minutes. Add the beef, sausage, and chopped spinach and mix to combine. Form the meat mixture into 1 1/2-inch balls (about 20 total) and place on the prepared baking sheet. Broil until cooked through, 6 to 8 minutes. Toss the pasta with the marinara sauce. Fold in 1 cup mozzarella, 1/4 cup of ricotta, then the remaining 2 cups of spinach and the meatballs. Transfer to a 3-quart baking dish. Sprinkle with the remaining 1/2 cup mozzarella and dollop with the remaining 1/4 cup ricotta. Broil until golden brown, 2 to 3 minutes.