Step 1

Heat oven to 375°F.

Step 2

Cook spaghetti as directed on package, omitting salt. Meanwhile, remove and discard casings from sausage if necessary. Crumble sausage into medium skillet; cook on medium heat until done, stirring frequently. Drain sausage; return to skillet. Stir in pasta sauce; simmer on medium-low heat 5 min., stirring occasionally.

Step 3

Drain spaghetti; place in large bowl. Add egg, Parmesan and 1 cup mozzarella; toss to coat. Spoon into 8-inch baking dish sprayed with cooking spray; top with sausage mixture and remaining mozzarella.

Step 4

Bake 15 min. or until heated through. Let stand 5 min. before cutting to serve.