Preheat oven to 350 degrees F. Grease a 2-quart rectangular baking dish; set aside. In a large skillet heat oil over medium-high heat. Add onion and sweet peppers; cook and stir for 5 minutes. Add zucchini and garlic; cook for 5 minutes more, stirring occasionally.
Add tomatoes, sausages, half of the Italian seasoning, salt, and black pepper to mixture in skillet. Bring to boiling; boil gently, uncovered, for 5 to 7 minutes or until most of the liquid has evaporated.
Meanwhile, unroll pizza dough on a lightly floured surface. Using a knife or pastry wheel, cut pizza dough into strips.
Remove skillet from heat. Stir in the Parmesan cheese and half of the mozzarella cheese. Spoon tomato mixture into prepared dish. Top with the remaining mozzarella cheese. Arrange pizza dough strips atop casserole in a lattice pattern. Sprinkle with remaining Italian seasoning. Bake, uncovered, about 30 minutes or until crust is brown and filling is bubbly. Let stand for 10 minutes before serving. If desired, top with snipped fresh rosemary.