Butternut Squash Lasagna

Name: Butternut Squash Lasagna
Ingredients: Kosher salt; 8 oz. lasagna noodles; Extra-virgin olive oil, for drizzling; 4 tbsp. butter; 2 cloves garlic, finely chopped; 3 tbsp. all-purpose flour; 3 c. whole milk; 3/4 tsp. freshly chopped thyme; Large pinch freshly grated nutmeg; 1/2 c. finely grated Parmesan; Freshly ground black pepper; 2 (10-oz.) bag frozen spinach, thawed and squeezed dry; 1 small butternut squash (about 1 pound), peeled, seeded, and cut into 1/4-inch-thick slices; 8 oz. shredded mozzarella