Vegetarian Baked Ziti

Name: Vegetarian Baked Ziti
Ingredients: cooking spray; 2 tablespoons olive oil; 2 cups cubed eggplant; 2 cups cubed zucchini; 2 large tomatoes, chopped; 1 medium red bell pepper, cubed; 1 medium onion, chopped; 3 cloves garlic, minced, or more to taste; 2 teaspoons Italian seasoning; 1 teaspoon salt; 1 (16 ounce) package ziti pasta; 1 (32 ounce) jar spaghetti sauce; 1 (15 ounce) can Italian-style diced tomatoes; 0.5 cup non-dairy Parmesan cheese substitute; 1 (16 ounce) package sliced fresh mozzarella cheese