Stuffed Shells with Spinach

Ingredients

• 4 cups shredded mozzarella cheese
• 1 carton (15 ounces) ricotta cheese
• 1 package (10 ounces) frozen chopped spinach, thawed and squeezed dry
• 1/2 teaspoon dried basil
• 1/2 teaspoon dried oregano
• 1/2 teaspoon salt
• 1/4 teaspoon pepper
• 1/4 teaspoon crushed red pepper flakes, optional
• 1 package (12 ounces) jumbo pasta shells, cooked and drained
• 3-1/2 cups spaghetti sauce
• Optional: grated Parmesan cheese