Cook pasta according to package direction omitting salt and fat; drain.

Preheat oven to 400°F.

Heat a large skillet over medium high heat. Add oil to pan. Add squash, zucchini and onion; saute 3 minutes. Remove from heat, stir in pasta, 1/2 cup mozzarella, herbs, 1/2 tsp salt and pepper.

Combine ricotta, remaining salt and egg. Stir into pasta mixture. Spoon into an 8" square glass baking dish coated with cooking spray; sprinkle with remaining mozzarella.

BAKE AT 400°F for 15 minutes or until bubbly and browned.