Easy Spinach Lasagna

Ingredients

• 1 (15- to 16-ounce) container whole-milk ricotta cheese
• 2 (10-ounce) boxes frozen spinach, thawed and excess liquid squeezed out
• 1 cup finely grated parmesan cheese (about 3 ounces)
• 2 medium garlic cloves, minced
• 1 large egg, lightly beaten
• kosher salt
• freshly ground black pepper
• 2 (14.5-ounce) cans tomato sauce or jarred marinara sauce
• 1 (8- to 9-ounce) box no-boil lasagna noodles (12 noodles)
• 1 pound whole-milk mozzarella cheese, sliced 1/4 inch thick
• vegetable or olive oil