8 ounces spaghetti, cooked, rinsed, cooled
2 cups tomato-based pasta sauce, divided
5 large eggs
1/2 cup chopped fresh Italian parsley, divided
1/2 teaspoon salt
1/2 teaspoon ground black pepper
1/8 teaspoon cayenne pepper
5 tablespoons olive oil
1 cup grated Parmesan cheese
Preheat broiler. Toss pasta and 1 cup pasta sauce in medium bowl to blend. Combine eggs, 1/4 cup parsley, salt, black pepper, and cayenne pepper in small bowl; whisk to blend.
Heat oil in large broilerproof nonstick skillet over medium-high heat. Add pasta and toss until warmed through, about 4 minutes. Pour egg mixture over; do not stir. Reduce heat to medium-low. Cook until eggs start to firm and bottom begins to brown, lifting sides occasionally to let uncooked egg run underneath, about 8 minutes. Remove skillet from heat. Sprinkle frittata with cheese. Broil until cheese melts, about 3 minutes.
Meanwhile, heat remaining 1 cup pasta sauce in saucepan over low heat. Using flexible spatula, loosen edges and bottom of frittata. Slide out onto plate. Sprinkle with remaining 1/4 cup parsley. Cut frittata into wedges. Serve, passing warm sauce separately.