Heat oven to 375
Cook pasta as directed on package, omitting salt
Meanwhile, heat oil in large skillet on medium heat. Add onions and garlic; cook 3-5 minutes or until crisp-tender, stirring frequently
Crumble sausage, then ground beef into skillet with cooked vegetables. Cook until ground meats are evenly browned, stirring occasionally. Remove from heat.
Mix egg, ricotta, and parmesan until blended
Drain pasta and spoon into a large bowl. Add pasta sauce mixture and ricotta mixture; mix lightly. Spoon into 13x9-inch baking pan sprayed with cooking spray; top with mozzarella.
Bake 20 mins or until heated through