Cook rotini in large pot of boiling salted water till tender but firm about 8 to 10 minutes, drain and rinse in cold water. Cover and refrigerate overnight. With the motor running, drop garlic cloves into the bowl of a food processor fitted with the steel blade. Mince, then add anchovies and process to combine. With the motor running, add oil in a thin stream until thickened.
Tear lettuce leaves into manageable pieces and place in a large salad bowl.
Add dressing and artichokes. Sprinkle with Parmesan cheese, toss , and top with croutons. Serve at once, passing the pepper mill for each person to add to taste. Drain, wrap in damp paper toweling, and refrigerate until ready to use, at least several hours. When ready to use, spinach will be dry and crisp.