Once water boils, remove pot from heat. Working with 4 noodles at a time, drop in water; let stand 1 to 2 minutes to soften. Use tongs to transfer 1 noodle to cutting board or work surface. Spread noodle with 3 tablespoons cheese mixture; roll up to enclose filling. Place, seam side down, in sauce-lined baking dish. Repeat with remaining softened noodles. Place 4 more noodles in pot. Fill with cheese mixture. Continue, using up all noodles and cheese mixture. Top with remaining tomato sauce. Sprinkle with mozzarella. Cover with lightly greased foil, greased side down.