Cheesy Spinach-Zucchini Lasagna

Name: Cheesy Spinach-Zucchini Lasagna
Cook time: 1 h 15 min
Total time: 1 h 15 min
Cuisine: Italian
Ingredients: 3 tablespoons extra-virgin olive oil, divided; 1 pound cremini mushrooms, thinly sliced; 1 clove garlic, minced; 0.5 teaspoon salt; 0.25 teaspoon ground pepper; 1 (11 ounce) package baby spinach; 1 large egg, lightly beaten; 1 (15 ounce) container part-skim ricotta cheese; 1.5 cups shredded part-skim mozzarella, divided; 1 cup grated Parmesan cheese, divided; 1 25-ounce jar low-sodium marinara sauce, divided; 6 sheets oven-ready lasagna noodles; 1 medium zucchini, cut lengthwise into 1/8-inch planks; Chopped fresh basil and/or parsley for garnish