How to Make It
Lightly coat a 5-quart slow cooker with cooking spray. Add the marinara sauce, pasta, zucchini, carrots, ricotta, mozzarella, Parmesan, olives, and water; stir to combine. Cover and cook on LOW until the pasta is tender, about 1 hour and 30 minutes to 2 hours.
Gently fold in the spinach until wilted. Spoon into serving bowls, and top evenly with the basil.